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Digitized  by  tine  Internet  Arciiive 

in  2010  witii  funding  from 
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http://www.archive.org/details/practicaltreatis1888evan 


A  FRACTip/VL  TREATISE 


v.;  ^ 


^  Went  SU  . .  :^ 
New  Yorl 

Artificial  Crown-  and  Bridge-Work. 


GEOEGE    EYANS. 


\A^ITH    500    ILLUSTRATIONS 


PHILADELPHIA: 

THE  S.  S.   WHITE   DENTAL  MFG.  CO. 
1888. 


"c^  \ 


tc 


V^ 


Copyright,  1888,  by  George  Evans. 


PRESS  OF  PATTERSON  tc   WHITE.    PMILA. 


To  the  fAemhers 

of  the 

First  District  Dental  jSociety  of  the  jState  of  J^ew  Yorl<, 

this  bool<  is  respectfully  dedicated 

by 

The  /iuTHDR. 


PREFACE. 

The  aim  of  tlir  aiitlior  in  jircparin*;'  this  treatise  is  to  sii[t[)ly 
an  admitted  want  in  dental  literature. 

Much  that  is  new  in  dentisti'v  and  much  more  that  is,  b}' 
maiiv  jiractitioiiers  at  least,  oidy  imperl'ectly  understood,  is 
invohed  in  crown-  and  bridge-work.  Properly  practiced  it 
approaches  a  fine  art;  hut  misapprehension  of"  the  princi[»les 
underlying  it,  lack  of  judgment  in  their  application,  a)id  im- 
proper practice  have  conspired  to  pre\eiit  its  general  acceptation 
by  the  })rotession,  and  it  has  in  conse([uence  been  oidy  partially 
indorsed  or  even  wholly  condemned  when  a  better  understan<hng 
would  liave  insured  its  hearty  approval.  Still,  its  possibilities 
are  seen  to  be  so  great  that  at  ])resent  no  other  branch  of 
dentistry  more  engages  the  attention  of  [mictitioiK'rs,  and  in  no 
other  is  a  livelier  interest  or  a  greater  desire  foi-  real  information 
manifested. 

The  subject  is  liere  presented  almost  wholly  from  the  practical 
stand-point,  in  the  behef  that  the  utility  and  esthetic  advantages 
of  crown-  and  bridge-work  may  l)e  thus  more  rea(hly  made 
apparent  to  the  practical  men  in  dentistry.  To  this  end  (lie 
various  methods  described  are  classified  in  systems,  and  their 
treatment  is  made  as  concise  as  their  importance  will  permit. 
Due  credit  is  given  where  the  methods  and  (k'scriptions  of  others 
are  used. 

Acknowledgment  is  gratefullj^  rendered  to  Drs.  IT.  A.  Parr, 
of  New  York  City,  E.  Parmly  Brown,  of  Flushing,  N.  Y.,  and 
M.  II.  Fletcher,  of  Cincinnati,  for  personal  assistance. 

George  Evans. 

New  York,  Aujrust,  1888. 


CONTEI^TS. 


PAGK 

Introduction 13 

Artificial  Crown-  and  Bridge-Work 17 

PART    I. 

PREPARATORY   TREATMENT    OP   TEETH   AND    ROOTS   FOR   CROWN-WORK. 

CHAPTER  I. 
The  Pulps  of  Teeth — Their  Preservation  or  Devitalization 22 

CHAPTER  II. 
Devitalization  of  the  Pulp  25 

CHAPTER  III. 
Pulpless  Teeth — Their  Treatment  and  Disinfection 29 

CHAPTER  ly. 
Chronic  Alveolar  Abscess 33 

CHAPTER  V. 

Shaping  Teeth  and  Roots  for  Crown-Work 37 

PART    II. 

ARTIFICIAL    CROWN-WORK. 
the  porcelain  system. 

CHAPTER  I. 

Porcelain  Crowns 44 

The  Bon  will  Crown 45 

The  How  Crowns  and  Methods 51 

The  Gates  Crown .58 

The  Foster  Crown 69 

The  Howland  Crown 59 

The  Logan,  Brown,  and  New  Richmond  Crowns 60 

Remarks  on  the  Use  of  Porcelain  Crowns 69 

9 


10  CONTENTS. 

CHAPTEK  ir. 

PAGE 

Porcelain  Crowx  with  Gold  Collar  Attachment 70 

CHAPTER  III. 
The  Weston  Crown 73 

CHAPTER  IV. 
Porcelain  Crowns  with  Rubber  or  Vulcanite  Attachment 76 

THE    gold    system. 

CHAPTER  V. 
Porcelain  and  Gold  Crown  without  a  Collar 77 

CHAPTER  VI. 
Gold  Collar   Crowns 79 

The  Construction  and  Adaptation  of  Collars 79 

CHAPTER  VII. 

Gold  Collar  Crowns  with  Porcelain  Fronts 84 

Incisors  and  Cuspids 84 

Bicuspids  and  Molars 87 

All-Gold  Collar  Crowns  for  Bicuspids  and  Molars  constructed  in  Sections  89 

CHAPTER  VIII. 

The  Gold  Seamless  Cap  Crown 99 

Incisors,  Cuspids,  and  Bicuspids 99 

Bicuspids  and  Molars 101 

CHAPTER  IX. 
Gold  Seamless  Contour  Crowns 105 

CHAPTER  X. 

Gold  Crowns  with  Porcelain  Fronts  for  Teeth  with  Living  Pulps  113 

CHAPTER  XI. 

Special  Forms  of  Gold  Crowns  with  Porcelain  Fronts 117 

The  Parr  Crown 117 

The  Leech  Crown 118 

The  Low  Crown 119 

CHAPTER  XII. 

Crowning  Fracturbd  Teeth  and  Roots,  and  Irregular  Teeth 121 

Longitudinal  Fracture  of  the  Crown  and  Root 121 

Fracture  of  the  Crown,  with  Slanting  Fracture  of  the  Root..... 122 

Methods  of  Crowning  in  Cases  of  Irregularity 122 


CONTENTS.  11 

CHAPTER  XIII. 

I'AGK 

Partial  Crowns 124 

CHAPTER  XIV. 

FlNISHINQ   AND    PoI.lSIIIVO  —  PrOCBSS    OF    CEMENTATION 128 

Finisliing  and  Polishing  Crown-Work 128 

Insertion  and  Cementation 128 

PAET    III. 

BRIDGE-WORK. 

CHAPTER  T. 
Construction  of  Bkidgk-VVork  ],37 

CHAPTER  II. 

Spkoial  Procks.ses  AND  APPLIANCES  IN  Bridge-Work 148 

CHAPTER  III. 
Extension  Bridges I.55 

CHAPTER  IV. 
Double  Bar- Bridges I59 

CHAPTER  V. 

RXTKNSIVK    AtI'LTCATIONS    OF    CPvOWN-    AND    BRIDGE- WoRK 102 

CHAPTER  VI. 
Repair  of  Crown-  or   BraDGE-WoRK 170 

CHAPTER  VII. 

Detachable  and  Rkmovable  Bridge-Work 172 

Dr.  Winder'.?  Sectional  Crown  Method 172 

Dr.  Litch's  Method 1 74 

Dr.  K.  W.  Starr's  Methods I77 

Dr.  C.  M.  Richmond's  Method 182 

Dr.  C.  S.  Waters's  Method 182 

Dr.  Parr's  Meth ods 183 

CHAPTER  VIII. 
Removable  Plate  Bridges 187 

CHAPTER  IX. 
The   Low    Bridge 198 

CHAPTER   X. 
Dr.  Knapp's  Methods 203 


12      .  -  CONTENTS. 

CHAPTER  XI. 

PAGE 

Dr.  Melotte's  Method  208 

CHAPTER  XII. 
Partial  Cap  and  Pin-Bridge  Methods 212 

CHAPTER  XIII. 

The  Mandrel  System 221 

Detachable  Bridge- Work 233 

CHAPTER  XIV. 

Porcelain  Bridge-Work 238 

Dr.  Brown's  Method 238 

PAET    IV. 

MATERIALS  AND   PROCESSES   USED    IN    CROWN-  AND    BRIDGE-WORK 

CHAPTER  I. 
Plate  and  Solders 249 

CHAPTER  II. 
Porcelain  Teeth 252 

CHAPTER  III. 
Molds  and  Dies...., 253 

CHAPTER  IV. 

SOLDER[NG 255 

CHAPTER  V. 
Instruments  and  Appliances 257 


INTRODUCTIOK 


Of  the  origin  of  the  art  of  dentistry  no  one  can  speak  with  cer- 
tainty, as  its  early  history  is  shrouded  in  the  mists  of  anti(^uity; 
])ut  dental  operations  are  recorded  in  \ery  remote  times. 

Kefereuces  are  made  to  the  art  in  tlie  writings  of  Hippocrates, 
in  the  tit'th  century  B.C.  Martial,  the  Latin  poet,  in  the  first 
century  B.C.,  says  that  a  Jloiuan  dentist  "  Cascellius  is  iti  the 
habit  of  fastening  as  well  as  extracting  the  teeth."  To  Lelius 
he  says,  "You  are  not  ashamed  to  purchase  teeth  and  hair;" 
and  adds  tliat  "  the  toothless  mouth  of  Egle  was  repaired  with 
hone  and  ivory;  "  also,  that  "  Galla,  more  refined,  removed  her 
artificial  teeth  during  the  night." 

Horace,  in  the  same  century,  cites  the  case  of  the  "  sorceresses 
Canidia  and  Sagana  running  through  the  city  and  losing  the  one 
her  false  hair,  the  other  her  false  teeth." 

Galen,  the  celebrated  physician,  in  the  second  century  a.d., 
also  speaks  of  the  art  of  dentistry  as  being  then  practiced. 

These  early  operations  were  limited  to  the  extraction  of 
offending  teeth  and  the  replacement  of  those  which  had  been 
lost  with  substitutes  which  were  retained  in  position  by  means 
of  narrow  bands  or  ligatures  attaching  them  to  the  adjoining 
natural  teeth,  and  without  the  use  of  plates.  Crude  as  thev 
were,  they  formed  the  first  expression  of  the  art  of  dentistry,  a 
beneficent  art  from  the  beginning,  in  that  it  sought  to  restore 
pathological  or  accidental  defects.  Confined  to  the  simplest 
operations,  it  existed  for  centuries,  and   then  was  apparently 

13 


14  INTRODUCTION. 

lost  during  the  Dark  Ages,  to  reappear  when  the  more  general 
diffiision  of  knowledge  ushered  in  the  modern  era  of  science 
and  invention. 

After  its  revival,  dentistry,  so  much  of  it  as  was  known,  was 
m  a  measure  a  secret  art,  tlie  practice  of  which  even  within  the 
memory  of  men  now  living,  and  they  not  the  oldest,  w^as  in- 
volved in  mystery;  but  recent  progress  has  lifted  the  veil,  and 
dentistry,  in  the  treatment  of  the  teeth  on  correct,  scientific, 
rational  principles,  has  developed  an  art  and  a  science  which 
have  given  it  honorable  rank  among  the  professions.  In  its 
two-fold  evolution  it  has  absorbed  from  every  available  source 
whatever  would  l^roaden  its  science  or  ^terfect  its  art.  It  calls 
to  its  aid  anatomy,  }:>hysiology,  pathology,  chemistr}^,  thera- 
peutics, metallurgy,  sculpture,  and  mechanics,  with  each  of 
which  it  stands  in  closer  or  more  remote  relation ;  and  the 
practitioners  of  dentistry  who  have  Ijecome  the  most  eminent 
and  useful  have  been  men  of  broad  attainments  and  great 
versatility  of  talent. 

In  the  history  of  all  progress,movements  apparently  of  a  more 
or  less  reactionary^  cliaracter  are  recorded.  In  the  useful  arts 
especially  it  is  not  uncommon  to  iind  a  return  to  forms  and 
methods  formerly  used  l)ut  long  since  discarded  and  forgotten. 
So  in  dentistry  we  find  methods  of  treatment  and  modes  of 
j)ractice  once  in  vogue  l)ut  long  fallen  into  disuse,  revived 
with  im})r()vements  and  modifications  that  stamp  them  as  practi- 
cally rediscoveries. 

These  movements  are  not  to  be  regarded  as  retrogressive, 
because  the  modifications  which  accompany  the  reintroduction 
of  practical  ideas  and  inventions  stamp  them  as  real  advances, 
and  indicate  clearly  that  the  cycle  of  knowledge  is  ever  widen- 
ing with  experience.  This  volume  demonstrates  how  modern 
dentistry  has  utilized  the  principles  of  some  of  the  simplest 
original  operations,  and  by  "  proving  all  things,  holding  fast  that 


INTRODUCTION.  15 

which  is  good,"  has  attained  its  present  honorable  position  in 
both  its  scientific  and  artistic  departments. 

The  history  of  dentistry  of  hitter  years  is,  in  In'ief,  a  recital  of 
progress  and  improvement.  Tlie  medical  profession  oflicially 
recog-nized  it  as  closely  allied  to  medicine  l>y  inviting  its  re})- 
resentatives  to  take  part  in  the  late  International  Medical  Con- 
gress on  the  footing  of  professional  equality. 

Such  is  the  position  which  dentistry  has  attained.  Much  of 
the  progress  which  has  made  its  present  elevation  possible  must 
be  credited  to  the  dental  profession  of  the  United  States,  which 
has  l)een  justly  termed  the  cradle  of  modern  dentistry.  Here 
the  validity  of  the  idea  that  scientific  knowledge  should  form 
the  basis  of  training  for  practice  was  first  demonstrated  l»y  the 
successful  establishment  of  dental  schools;  here  the  first  journal 
for  the  interchange  among  dentists  of  thought  and  experience 
was  founded;  here  the  first  association  having  for  its  object  the 
uplifting  and  upholding  of  dentistry  by  the  niutual  helpfulness 
of  its  })ractitioners  had  its  origin;  here,  in  a  word,  dentistry 
was  first  divorced  from  mystery,  here  it  first  passed  the  narrow 
confines  of  a  mere  handicraft  and  earned  for  itself  the  right  to 
be  classed  among  the  learned  and  liberal  jirofessions. 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

GtORGt  tVANS, 


49  West  39th  St.,  N.  Y.  City. 

Modern  artificial  crown-  and  bridge-work  belongs  to  the  de- 
partment of  dentistry  until  recently  termed  "  mechanical,"  but 
the  judgment,  skill,  and  scientific  information  required  place  it 
far  above  ordinary  mechanical  dentistrj^  which  has  sunk  to  a 
low  estate  since  the  introduction  of  vulcanite.  To  such  an 
extent  has  vulcanite,  by  reason  of  its  cheapness  and  ease  of 
manipulation,  superseded  other  materials  demanding  greater 
knowledge  and  skill  in  their  manipulation,  as  to  retard  the 
higher  development  of  prosthetic  dentistry,  and  indeed,  to  di- 
vest it,  in  the  hands  of  those  who  depend  upon  the  former,  of 
the  dignity  which  should  belong  to  dentistry  as  a  profession. 

But  modern  crown-  and  bridge-work,  properly  understood  and 
properly  performed,  takes  high  rank  in  dental  art,  and  ofiers 
wide  scope  for  versatility  of  talent  and  inventive  genius.  The 
varied  and  complicated  cases  presenting  for  treatment  frequently 
suggest  to  the  expert  novel  contrivances  and  methods  of  con- 
struction and  application.  Successful  practice  of  crown-  and 
bridge-work  depends  upon  a  thorough  mastery  of  the  underlying 
principles,  and  expertness  in  the  processes  involved,  governed 
by  sound  judgment  and  perfect  candor.  The  interests  of  the 
patient  should  be  paramount  to  every  other  consideration,  and 
after  a  careful  examination  he  should  be  given  an  accurate  state- 
ment of  the  applicability  of  the  system  to  his  case,  in  respect  to 
usefulness,  appearance,  durability,  and  comfort,  as  compared 
with  other  processes  and  appliances  in  use. 

Surgical  and  mechanical  operations  of  the  most  delicate  nature 

2  17 


18  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

are  required.  Nothing,  indeed,  in  dentistry  demands  finer  ma- 
nipulation. A  practical  consideration  of  the  subject  will  show 
that  a  knowledge  of  anatomy,  pathology,  and  therapeutics,  and 
as  well  mechanical  and  artistic  skill,  are  necessary  to  the  correct 
treatment  of  cases  and  the  proper  performance  of  the  operations 
indicated.  Among  the  principal  steps  in  an  operation  may  be 
named,  first,  the  preparatory  treatment  of  the  natural  roots  and 
teeth  for  the  final  process,  involving  the  diagnosis  of  present  or 
probable  lesions  and  the  prescription  of  whatever  remedial  or 
prophylactic  measures  may  be  needful ;  second,  in  crown-work, 
the  adaptation  of  the  artificial  crowns  to  the  cervical  portion  of 
the  natural  roots  and  the  contiguous  membranes,  and  the  restora- 
tion of  the  articulation  and  the  anatomical  contour;  and,  in 
bridge-work,  the  selection  of  suitable  teeth  or  roots  for  founda- 
tion piers  or  abutments,  and  the  choice  and  adaptation  in  con- 
structive practice  of  the  forms  which  will  insure  the  highest 
degree  of  stability  and  best  sustain  the  force  of  occlusion,  thereby 
avoiding  abnormal  positions  and  conditions. 

The  practice  of  crown-  and  bridge-work  by  dentists  possessing 
the  requisite  attainments  and  governed  by  correct  ethical  prin- 
ciples gives  results  which  will  establish  its  value,  remove  erron- 
eous impressions,  and  insure  a  wide  professional  and  public 
indorsement  of  this  important  branch  of  prosthetic  dentistry. 
Its  ■  extraordinary  facilities  for  preserving  and  replacing  teeth 
arc  graduall}^  making  for  it  the  position  in  dental  art  which  it 
merits. 


PAET   I. 

PREPARATORY  TREATMENT  OF  TEETH  AND  ROOTS  FOR 

CROWN-WORK. 


PREPARATORY  TREATMENT  OF  TEETH  AND 
ROOTS  FOR  CROWN-WORK 

Preparatory  treatment  of  teeth  and  roots  for  crown-work 
includes,  in  addition  to  the  shaping  required  to  fit  them  for  the 
reception  of  the  crowns,  the  bringing  about  of  the  healthiest 
possible  condition  in  the  teeth  and  roots  and  the  adjacent  parts, 
as  the  cure  of  existing  lesions,  the  removal  of  calculus  where 
necessary,  and  the  adoption  of  such  measures  as  shall  prevent 
the  recurrence  of  old  troubles  or  the  inception  of  new. 

Notwithstanding  all  that  advanced  knowledge  of  therapeutical 
agents  and  skill  in  their  use  permit,  there  are  many  teeth  and 
roots  which  cannot  be  rendered  suitable  for  the  successful  appli- 
cation of  crown-  or  bridge-w^ork.  Roots  which  are  permeated 
and  softened  by  decay,  exposed  or  loosened  from  absorption  of 
the  gums  and  alveoli,  or  aftected  with  irremediable  disease  of 
the  investing  membranes,  should  be  thus  classed.  Cases  in 
which  abscess  with  necrosis  has  extensive!}^  impaired  the  walls  of 
the  alveoli  are  equally  intractable. 

Experience  shows  that  the  results  in  this  department  of  den- 
tistry depend  largely  upon  diathesis  or  constitutional  tendency 
and  upon  the  attention  given  to  the  preservation  of  the  health 
of  the  mouth  ;  and  these  conditions  should  be  carefully  estimated 
in  the  selection  of  a  system  of  treatment  and  the  method  of  its 
application. 


•21 


CHAPTEE    I. 

THE   PULPS   OF   TEETH— THEIK  PEESEPvVATION   OR   DEVITALI- 
ZATION. 

The  preservation  of  the  vitality  of  the  pulps  of  the  teeth  is  a 
matter  of  as  much  importance  in  connection  with  crown-  and 
bridge-work  as  in  any  other  class  of  operations,  though  the 
excision  of  natural  crowns  for  the  purpose  of  utilizing  the  roots 
as  abutments  for  bridge-work  is  extensively  practiced,  and 
is  defended  on  the  theory  that  the  vitality  of  the  dentine  is  main- 
tained by  the  cementum  after  the  extirpation  of  the  pulp,^ 

Dr.  C.  F,  W.  Bodecker,  discussing  the  subject  of  the  "  Dis- 
tribution of  Living  Matter  in  Human  Dentine,"  says,^ — 

"•  1st.  The  dentinal  canaliculi  are  excavations  in  the  basis-sub- 
stance of  the  dentine,  each  containing  in  its  center  2^  fiber  of 

^Dr.  J.  L.  Williams  says,  "  The  life  and  vitality  of  the  cementum  remain  in- 
tact and  uninjured,  and  even  the  dentine  may,  and  undoubtedly  does,  retain  a 
certain  amount  of  vitality,  for  something  analogous  to  a  healing  process  takes 
place  at  the  ends  of  the  broken  fibrillse  next  to  the  pulp-chamber,  and  by  one  of 
those  wonderful  provisional  conditions,  which  we  so  often  meet  with  in  the 
economy  of  the  animal  kingdom,  nature  reverses  or  changes  the  origin  of  nutri- 
tive supply,  and  the  material  for  maintaining  the  continued  vitality  of  the  den- 
tine comes  through  the  cementum." 

He  further  says,  "  Every  practicing  dentist  has  observed  that  a  tooth  which  is 
removed  from  contact  with  the  fluids  of  the  mouth  changes  color.  This  change 
in  color  is  largely  the  result  of  the  evaporation  of  the  water  from  the  organic 
portion  of  the  tooth.  Now,  if  the  apical  foramen  of  such  a  tooth  be  clo.«ed,  and 
the  tooth  be  then  placed  in  water,  or  preferably,  glycerin  and  water,  in  a  short 
time  it  will  regain  nearly  its  original  color,  and  at  the  same  time  it  will  be  found 
that  it  has  increased  in  weight.  This  means,  of  course,  that  the  entire  tooth  has 
absorbed  from  the  surface  a  certain  quantity  of  the  fluid,  and  this  fluid  has  pene- 
trated every  part  of  the  solid  structure  of  the  tooth.  Will  any  one  doubt,  with 
these  facts  in  view,  that  when  the  tooth  is  in  position  in  the  jaw,  and  surrounded 
by  all  the  delicate  adjustments  furnished  by  nature,  there  may  be  a  circulation 
of  nutrient  fluids  throughout  the  entire  root  after  the  removal  of  the  pulp  ?" 

It  is  difficult  to  understand  how  a  f  aturation  can  be  compared  to  an  infiltration 
controlled  by  vital  circulation. — G.  E. 

'^Dental  Cosmos,  vol.  xx,  page  6-')G. 
22 


DEVITALIZATION  OF  THE  PULP.  27 

remains  in  the  tubuli,  and  increases  the  difficulty  of  producing 
an  aseptic  condition  of  the  dentine.  It  is  asserted  that  arsenic 
produces  devitalization  of  the  fibrillfe  as  far  as  the  cementum, 
and,  in  some  cases,  even  involves  that  tissue,  while  in  instanta- 
neous extirpation  of  the  pulp  the  vitality  of  the  dentine  is  to 
some  extent  preserved  by  the  circulation  it  receives  from  the 
cementum. 

Practical  experience,  however,  shows  that  instant  devitaliza- 
tion or  extirpation  is  the  most  satisfactory  in  general  and  final 
results.  Arsenic,  when  used,  should  be  applied  directly  to  the 
pulp  in  the  smallest  quantity  possible  to  effect  its  devitalization, 
and  securely  sealed  in  the  cavity.  The  application  should  be 
kept  in  position  no  longer  than  is  necessary  to  effect  the  devitali- 
zation of  the  pulp. 


Plate  IV. 


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CHAPTER    III. 


PULPLESS   TEETH,— THEIR   TREATMENT  AND   DISINFECTION. 


Pig.  4. 


The  treatment  of  pulpless  teeth  or  roots  consists  in  as  thorough 
a  performance  as  possible  of  the  following  operations  : 

1st.  Removal  of  the  contents  of  the  canals. 

2d.  Disinfection  of  the  root-canals  and  the  dentine,  and  the 
establishment  of  permanent  aseptic  conditions  by  mummification 
of  the  contents  of  the  tubuli. 

3d.  Closure  of  the  apical  foramen. 

A  knowledge  of  the  usual  positions  of  the  root-canals  in  the 
different  teeth  is  essential  for  a  generally  successful  performance 
of  these  operations,  which  are  greatly  facilitated,  in  crown- work, 
by  the  ease  with  which  direct  access  to  the 
root-canals  is  obtained.  (See  Plate  IV.)^  An 
opening  is  first  made  into  the  center  of  the 
pulp-chaml)er  in  a  line  with  the  root-canals 
sufficient  to  give  free  and  direct  access  to 
them,  and  any  remaining  portion  of  the  pulp 
removed  with  broaches.  The  canals  are  then , 
guided  by  frequent  explorations  with  a  fine 
probe,  carefully  enlarged  with  Gates-Glidden 
drills  (Fig.  4).  At  least  three  sizes — large, 
medium,  and  small — of  drills  each  for  the 
right-angle  and  the  direct  hand-piece  are  required.*  Very  little, 
if  any,  pressure  should  be  put  upon  them  when  in  motion,  as  they 
will  move  forward  of  themselves.     Under  pressure  a  false  passage 

1  Plate  IV. — Figs.  1  and  2  represent  the  superior  and  inferior  teeth  in  trans- 
verse section  through  the  base  of  the  pulp-chamber  in  the  crown,  showing  the 
entrance  to  the  root-canals. 

Figs.  3  and  4  represent  the  superior  and  inferior  teeth  in  transverse  section 
through  the  root-canals  as  they  diverge  from  the  pulp-chamber. 

aa,  bb,  cc,  dd,  Jt\  dd,  and  ee,  Figs.  3  and  4,  show  the  relative  shapes,  whether 
circular,  oval,  or  flattened,  of  the  root-canals  in  the  teeth  they  severally  repre- 
sent. 

29 


30 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


in  a  curved  root  is  possible,  or  the  small  drill  might  be  broken 
oif  or  forced  through  the  apical  foramen  with  disastrous  conse- 
quences, where  alveolar  abscess  did  not  exist.     ISTeither  should 


Fig.  5. 


Fig.  6. 


Fig.  7. 


they  be  forced  into  canals  closed  by  calcification.  A  slight  pain 
is  usually  experienced  when  they  enter  the  zone  of  sensibility 
formed  by  the  cementum  which  composes  the  end  of  the  root. 
The  probe-like  points  of  these  drills  do 
not  cut,  but  simply  guide  the  drills,  and 
confine  them  to  the  line  of  the  canal. 
The  use  of  these  drills  is  condemned 
by  some  for  reasons  attributable  to  their 
careless  or  improper  employment,  but 
they  are  indorsed,  in  experienced  hands, 
for  their  adaptability  to  the  w^ork  under 
consideration. 

The  cavity  of  the  root-canal  having 
l)een  properly  opened  up  and  its  con- 
tents removed,  it  is  syringed  out  with 
tepid  water,  and,  in  case  the  pulp  has 
been  long  devitalized,  wdth  peroxide  of 
I  Ivydrogen,  and  then  dried  with  cotton. 
The  mouth  is  then  properly  protected 
with  napkins,  and  a  current  of  hot  air 
introduced  into  the  pulp-chamber  by  a 
hot-air  syringe  (Fig.  5),  at  a  tempera- 
ture higher,  as  it  leaves  the  nozzle,  than  is  comfortable  for  the 
finger.  This  heats  any  part  of  the  crown  remaining,  and  the 
lower  portion  of  the  root.  A  silver  probe,  connected  wdth  an 
oval-shaped  mass  of  silver  or  copper  (Fig.  6)  which  has  been 
heated  to  a  dull  red  heat,  is  then  introduced  into  the  root-canal 


TREATMENT  OF  PULPLESS  TEETH.  31 

(Fig.  7).  As  silver  possesses  remarkable  properties  as  a  ther- 
mal conductor,  the  heat  is  transmitted  to  the  point  of  the  probe 
very  rapidly.'  The  probe  being  inserted  as  far  as  possible  up 
the  canal,  the  patient  is  directed  to  raise  the  hand  as  a  signal 
should  the  heat  cause  pain,  when  the  probe  must  be  moved  up 
and  down,  or  withdrawn  for  a  moment.  This  procedure,  follow- 
ing the  previous  application  of  hot  air  with  the  sj'ringe,  evapor- 
ates the  moisture  and  gases  from  the  root-canals  and  the  open 
ends  of  the  tubuli.  The  heat  also  acts  as  a  germicide,^  and  car- 
bonizes any  organic  matter  the  instrument  reaches.  While  in 
this  heated  and  dried-out  condition  the  dentine  is  saturated  with 
an  antiseptic  agent,  which  should  possess  such  properties  as  to 
make  its  action  efiicient  and  its  effects  permanent.  At  present, 
experience  finds  bichloride  of  mercury — ^-^  solution — or  iodo- 
form most  suitable  for  the  purpose.'^  When  both  agents  are 
used,  the  sublimate  solution  should  be  applied  first,  then  the 
iodoform,  after  the  canal  has  been  dried.  Iodoform  is  most 
convenienth'  applied  in  a  saturated  solution  in  sulphuric  ether. 
Carbolic  acid  and  like  agents  are  being  discarded  for  various 
reasons,  among  which  are  their  inefficiency  and  their  eventual 
absorption  from  the  dentine. 

After  one  or  more  treatments  in  the  manner  described,  the 
canal  is  dried  and  the  foramen  closed.  Of  the  man}-  materials 
used  for  the  purpose,  gutta-percha  is  most  approved.  When 
used  in  the  form  of  chloro-gutta-percha,  a  good  method  is  to  dip 
a  few  shreds  of  cotton  in  the  solution,  press  out  the  surplus,  and 
gently  pack  (not  push)  them  lengthwise  into  the  extremity  of  the 
canal.  Cotton  so  prepared  is  incorruptible,  and  when  properly 
inserted  it  effectually  closes  the  foramen,  obviates  any  danger  of 

^  As  a  test  of  the  thermal  conductivity  of  silver,  heat  the  oval  portion  of  this 
instrument  to  a  dull  red  heat,  and  place  the  point  of  the  probe,  which  is  as  fine 
as  a  broach,  in  a  little  water  on  the  end  of  a  cork.  The  water  will  boil  and 
evaporate  in  a  few  seconds. 

2  To  accomplish  the  same  end,  Dr.  Register  uses  fine  tubes  of  platinum,  through 
which  hot  air  is  forced,  but  this  is  hazardous  near  an  open  foramen,  less  efl'ective, 
and  less  convenient  than  the  method  detailed. 

■'  lodol  or  the  dental  tincture  of  iodine  can  be  used  in  place  of  iodoform  should 
the  odor  of  the  latter  render  it  objectionable.  A  small  quantity  of  oil  of  %vinter- 
green  added  to  the  solution  aids  in  disguising  the  odor. 


32  ARTIFICIAL  GROWN-  AND  BRIDGE-WORK. 

air  or  the  solution  of  gutta-percha  being  pressed  through,  and  is 
easily  removed  should  any  subsequent  condition  require  it.  The 
canal  is  then  filled  with  gutta-percha  or  any  other  material 
preferred.  Ordinary  gutta-percha  should  be  used  to  close  a 
foramen  when  an  abscess  has  just  been  treated  by  injecting 
throuo:h  it. 

Successful  treatment  of  pulpless  teeth  depends  not  on  "  imme- 
diate root-filling  after  extirpation  of  the  pulp,"  hut  upon  imme- 
diate roof-Jjlliiig  after  producing  a  thorough  aseptic  condition  of  the 
canals  and  dentine. 

Ample  room  should  be  left  in  any  root-canal  which  is  to 
receive  the  post  of  a  crown,  as  any  part  of  the  canal  not  occu- 
pied by  the  post  will  be  filled  by  the  retaining  material. 

A  pulpless  tooth  presented  for  crowning,  the  roots  of  which 
have  been  treated  and  filled  in  some  previous  operation,  should 
be  carefully  examined,  and  if  any  doubt  is  entertained  as  to  its 
hygienic  condition  it  should  receive  the  antiseptic  treatment 
above  described,  as  the  ultimate  success  of  crown-work  depends 
largely  upon  the  thoroughness  of  these  preliminary  operations. 


CHAPTER   IV. 

CHRONIC  ALVEOLAR  ABSCESS. 

Many  teeth  and  roots  presented  for  erown-work  are  affected 
with  chronic  alveolar  abscess.  A  general  description  of  an 
effective  method  of  treatment  is  therefore  properly  associated 
with  a  discussion  of  the  subject. 

The  cause  of  chronic  alveolar  abscess  will  be  found  in  a  con- 
tinuation of  those  conditions  which  originally  produced  the  acute 
form.  The  tooth  or  root  being  pulpless,  septic  gases,  generated 
by  the  decomposition  of  organic  matter  in  the  root-canal  and  in 
the  tubuli  of  the  dentine,  find  an  outlet  through  the  open  foramen 
into  the  apical  space,  causing  pericementitis  and  formation  of 
pus.  The  general  treatment  consists  in  the  removal  of  all  septic 
matter  and  gases  from  the  root-canal  and  dentinal  tubuli,  the 
destruction  of  the  pus-sac,  the  application  of  suitable  therapeutic 
agents,  and  the  adoption  of  measures  to  prevent  further  formation 
of  pus. 

Chronic  alveolar  abscess  is  usually  found  in  the  following 
forms :  1st.  Abscess  with  a  fistulous  opening  in  the  gum,  and 
accessible  through  the  root-canal  and  foramen  of  the  root.  2d. 
Abscess,  with  fistulous  opening  but  not  accessible  through  the 
apical  foramen.  3d.  Abscess  from  which  pus  discharges  through 
the  apical  foramen  and  root-canal  with  no  opening  through  the 
gum. 

In  the*  treatment  of  abscess  of  the  first  form,  the  canal  should 
be  enlarged  as  described  in  the  treatment  of  pulpless  teeth,  and 
the  foramen  opened,  if  possible,  with  a  smooth  broach  without 
the  use  of  a  drill.  Tepid  water  is  then  forced  through  the 
foramen  with  a  fine-pointed  syringe  (Fig.  8)  introduced  well  up 
the  canal,  and  packed  in  with  gutta-percha,  or  pumped  up  with 
cotton   on  a  broach   until   it   passes  into  the  abscess  and  out 

3  83 


34 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


through  the  fistula.  Peroxide  of  hydrogen  is  next  used  in  the 
same  manner,  until  it  ceases  to  foam  as  it  passes  from  the  abscess. 
Aromatic  sulphuric  acid,  either  pure  or  diluted,  is  then  applied 
as  a  germicide  and  powerful  astringent. 

In  abscesses  of  the  second  form,  where  it  is  impracticable  to 
treat  through  the  foramen,  the  canal  should  he  thoroughly  disin- 
fected, and  a  direct  opening  into  the  abscess  effected  by  the  track 
of  the  fistula,  enlarging  it  if  necessary.  The  abscess  should 
then  be  thoroughly  injected  with  peroxide  of  hydrogen  and 
afterwards  with  aromatic  sulphuric  acid,  by  introducing  the  fine 
point  of  a  syringe  into  its  deepest  parts.     The  fistula  must  be 

kept  open  by  inserting  in  it,  at  each 
injection,  a  strand  of  twisted  cotton 
saturated  with  oil  of  cloves,  the  pa- 
tient being  directed  to  remove  it  in 
a  few  hours,  or  the  next  day,  for 
which  purpose  the  end  should  be 
left  protruding.  When  the  apical 
foramen  is  open,  one  injection  is  usu- 
ally sufi&cient  to  cure  an  abscess ;  but 
when  the  foramen  is  closed  and  the 
abscess  is  treated  through  the  gum, 
several  injections  are  sometimes  ne- 
cessary. 

In  case  of  "  blind  abscess,"  first 
clean  and  disinfect  the  root-canal, 
then  at  intervals  inject  the  abscess 
through  the  foramen  with  peroxide  of  hydrogen  until  the  for- 
mation of  pus  ceases,  placing  cotton  saturated  with  oil  of  cloves 
loosely  in  the  canal  to  exclude  foreign  substances.  Should  this 
treatment  fail,  an  opening  through  the  gum  into  the  abscess  must 
be  obtained  either  with  a  lance  and  drill,  or  a  trephine,  and  the 
same  course  pursued  as  in  the  first  form  of  abscess. 

An  entrance  into  the  apical  space  can  be  made  almost  pain- 
lessly in  the  following  manner,  as  described  by  Dr.  G.  V.  Black:' 
"  The  mucous  membrane  is  first  dried  at  the  point  at  which  it  is 
desired  to  make  the  opening,  and  napkins  are  so  placed  as  to 

^  American  System  of  Dentistry,  vol.  i,  page  928. 


CHRONIC  ALVEOLAR  ABSCESS.  35 

keep  it  dry.  Tneu  a  plugging-iustrument  with  fairly  sharp 
serrations  and  of  convenient  shape  is  selected.  The  point  of 
this  is  dipped  into  a  95-per-cent.  solution  of  carbolic  acid,  and  a 
drop  convej'ed  to  the  mucous  membrane ;  this  will  at  once  pro- 
duce a  white  eschar.  Then  a  slight  scratching  motion  with  the 
serrated  point  is  begun,  with  the  view  of  removing  the  tissue 
that  is  whitened.  This  is  continued  until  the  carbolic  acid  is 
thick  with  the  debris  of  the  tissue  torn  up,  then  it  is  dried  out 
and  another  drop  added,  as  before,  and  the  process  continued. 
This  is  repeated  as  often  as  may  be  necessary,  going  deeper  and 
deeper  into  the  tissue  in  the  desired  direction  until  the  bone  is 
laid  bare.  Then  a  fresh  drop  of  the  acid  is  placed  on  the  bone 
and  the  periosteum  carefully  raised  over  a  sufhcient  space ;  then 
with  a  sharp  chisel  cut  through  to  the  peridental  membrane. 
This  Avill  generally  cause  some  pain  and  some  bleeding,  but 
after  giving  a  little  time  for  this  to  cease,  and  adding  more  of 
the  acid,  the  apical  space  can  usually  be  reached  without  diffi- 
culty. Xo  blood  should  be  drawn  at  any  time  during  the  opera- 
tion, except  in  penetrating  the  wall  of  the  alveolus.  In  doing 
this  no  tissue  is  removed  until  it  is  anesthetized  by  the  carbolic 
acid.  This  is  a  little  tedious,  but  it  is  almost  painless,  and  the 
general  effect  is  usually  better  than  by  other  modes  of  penetrat- 
ing the  apical  space.  The  carbolic  acid  has  the  effect  of  modi- 
fying the  pain,  and  the  opening  left  does  not  close  so  readily.'" 

After  the  abscess  has  been  cured,  the  root-canals  are  treated 
and  tilled  as  described  on  page  29. 

In  place  of  aromatic  sulphuric  acid,  if  preferred  or  should  the 
case  suggest  it,  either  carbolic  acid,  the  sublimate  solution  (3-J5VD")' 
or  any  other  suitable  therapeutic  agent  can  be  used,  but  most  of 
them  will  be  found  less  prompt  and  less  effective,  especially  if  a 
slightly  necrosed  state  of  the  wall  of  the  alveolus  exists.^ 

Amputation  of  the  Apex  of  a  Root. — In  long-neglected  alveolar 
abscess,  the  pus-cavity  occasionally  involves  the  alveolus  in  such 
a  way  as  to  destroy  a  considerable  portion  of  the  pericementum 

^For  an  extensive  consideration  of  this  subject  the  reader  is  referred  to  Dr.  J. 
X.  Farrar's  articles  on  "  Sulphuric  Acid  v.  Creasote  in  Treatment  of  Alveolar 
Abscess,"  commencing  Dental  Cosmos,  vol.  x.\,  No.  7,  and  Dr.  G-  V.  Black's 
article  in  the  "  American  System  of  Dentistry,"  vol.  i,  page  929. 


36 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


Fig.  9. 


of  the  end  of  the  root.  The  cementum  of  that  part  is  conse- 
quently devitalized,  and  the  portion  of  the  root  affected  becomes 
degenerated  in  structure,  and  saturated  with  septic  matter.  In 
this  condition  it  acquires  the  character  of  a  foreign  substance, 
proves  a  constant  source  of  irritation,  and  defies  all  efforts  of  the 
membranes  to  perfectly  inclose  or  encyst  it. 

In  such  cases  amputation  of  the  portion  of  the 
root  which  is  denuded  of  pericementum  is  the 
best  course  to  pursue.  An  opening  is  made  in 
the  soft  tissues  above  the  affected  part  with  the 
lancet  or  trephine,  and  gradually  enlarged  with  a 
tent  of  lint  or  cotton  until  the  diseased  territory 
is  fully  exposed  (Fig.  9),  when  the  devitalized  end 
of  the  root  and  any  necrosed  bone  in  the  territory 
are  removed  with  a  fissure-drill,  and  the  end  of 
the  root  smoothed.  The  root-canal  is  then  closed 
with  gutta-percha  passed  through  from  within,  the 
surplus  being  trimmed  ofl"  on  the  outside.  Cocaine 
can  be  used  in  this  operation. 
The  orifice  of  the  cavity  in  the  gum  should  be  kept  open  until 
the  cavity  is  filled  by  granulation.  When  the  healing  process  is 
completed,  crown-work  can  be  proceeded  with. 

The  amputation  of  roots  requires  skill  and  experience,  and 
had  better  be  confined  to  the  incisors  and  cuspids. 


CHAPTEE  V. 


SHAPING  TEETH   AND   KOOTS   FOR   CROWN-WORK. 


The  principles  governing  the  process  of  shaping  a  natural 
crown  or  root  for  any  style  of  artificial  crown  with  a  collar 
attachment  require  that  the  cervical  portion  of  the  natural  crown 
and  root  should  be  given  a  form  that  has  longitudinally-parallel 
sides  gauged  to  the  line  of  the  periphery  of  that  part,  and  that 
any  of  the  coronal  section  present  below  it  shall  be  reduced  at 
least  sufficiently  in  size  to  come  within  this  line.  Such  a  form 
is  necessary  to  admit  of  a  perfect  adaptation  of  the  collar. 

The  coronal  section  of  a  natural  crown  to  be  prepared  is 
usually  first  ground  on  the  occluding  surface  with  as  large  a 
conindum-wheel  as  the  case  will  conveniently  admit  (Fig.  10). 

Fig.   10. 


Molars  and  bicuspids  for  all-gold  crowns  should  have  enough 
substance  removed  to  make  a  small  space  between  them  and 
the  antagonizing  teeth.  The  approximal  surfaces  are  removed 
straight  from  the  cervical  border  to  the  occluding  surface,  using 
rubber  and  corundum  disks  (Fig.  11)  and  tiles,  and  last  of  all, 
as  injury  to  the  approximal  teeth  is  then  more  easily  avoided,  the 
labial  and  palatal  portions,  for  which  small  corundum  points 
(Fig.  12)  and  wheels  are  best  adapted.  The  corners  are  then 
rounded.  The  cervical  portion,  which  includes  the  junction  of 
the  dentine  and  enamel,  is  trimmed  so  that  the  sides  as  illus- 
trated at  A,  Fig.  13,  are  level  and  parallel  with  the  line  of  the 

37 


38 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


root,  and  as  deep  as  the  collar  is  to  be  placed  (Fig.  14).  For 
this  purpose,  small  corundum  points,  trimmers,  and  files  can  be 
used.    Fig.  15  illustrates  a  drill,  which  in  the  ordinary  hand-piece 


Big.  it. 


Fig.  12. 


or  in  the  right-angle  attachment  will  easily  and  quickly  accom- 
plish this.  Fig.  16  illustrates  another  form  which  can  be  used  in 
a  hand  socket,  or  by  revolving  it  rapidly  with  the  engine.  The 
points  should  be  tempered  very  hard ;  files  shaped  as  shown  in 
Fig.  17  are  useful  in  rounding  angular  portions. 

In  pulpless  teeth,  the  use  of  excising  forceps  should  be  avoided 
unless  the  parts  admit  of  it  without  serious  shock  to  the  root. 
The  best  plan  is  to  make  a  succession  of  holes  across  the  portion 
to  be  removed  with  a  spear-shaped  drill,  and  then  cut  between 

Fig.  1?..       Fig.  14.  Fig. 15.  Fig.  16.     Fig.  17.  Fig.  18.       Fig.  19.     Fig.  20. 


I 


the  holes  with  a  fissure-bur  or  corundum  disk,  which  will  permit 
of  easy  removal  of  the  part  (Fig.  18). 

In  preparing  incisors  and  cuspids  for  gold  collar  crowns  with 
porcelain  fronts,  where  the  pulp  is  to  be  preserved,  the  labial 
surface  and  incisive  edge  should  be  ground  down  as  much  as 
possible  without  exposing  the  pulp  or  subjecting  it  to  irritation ; 
the  palatal  portion  at  an  angle  from  the  cervical  border  to  the 
incisive  edge,  enough  to  level  its  prominences  of  contour  and 


SHAPING  TEETH  AND  ROOTS  FOR  CROWN-WORK. 


39 


form  a  slight  space  between  it  and  the  antagonizing  teeth  (Fig.  19). 
Pulpless  incisors  and  cuspids  should  be  ground  to  the  margin 
of  the  gum  at  the  labial  portion,  and  slightly  above  the  margin 
on  the  posterior  half  (Fig.  20).  Bicuspids  which  are  to  have 
porcelain  fronts  are  given  the  same  general  form  (Fig.  21). 

Bicuspids  and  molars  with  or  without  pulps,  for  all-gold  crowns, 
should  have  as  much  of  the  natural  crown  left  as  possible,  as  it 
offers  a  form  of  attachment  for  the  artificial  crown  which  is 
more  secure  and  more  convenient  than  is  attained  by  any  other 
method  (Figs.  22  and  23). 

For  the  porcelain  system,  incisor,  cuspid,  and  posterior  roots 
are  usually  ground  level  with  the  margin  of  the  gum.    The  palatal 


Fig.  21. 


Ftg.  22. 


Fig.  23. 


Fig.  24. 


portion  is  favored  in  some  cases  by  leaving  it  a  triiie  above  the 
margin.  The  root-canal  is  shaped  to  the  form  of  the  post  or  pin 
so  that  it  shall  fit  it  tightly.  For  details  see  the  articles  on  the 
Bon  will  and  Logan  crowns.  The  occluding  edges  or  surfaces  of 
antagonizing  teeth  should  be  removed  sufficiently  to  allow  ample 
space  for  the  artificial  crowns  or  to  favor  them  in  the  act  of  occlu- 
sion. Corundum  or  composition  wheels  or  points  should  be  kept 
wet  and  cool  in  these  and  other  operations  in  the  mouth. 

Special  Preparation  of  Badly  Decayed  Teeth  or  Hoots. — The  tem- 
porary exposure  of  the  end  of  a  root  or  of  the  cervical  portion  of 
a  crown  for  the  purpose  of  facilitating  or  simplifying  a  crowning 
operation,  especially  in  the  adaptation  of  a  collar  or  band,  is 
ettected  by  inserting  in  the  ])ulp-chamber  or  the  root-canal  a 
piece  of  gutta-percha  large  enough  to  admit  of  a  portion  being 
brought  over  against  the  investing  membranes,  to  compress  them 
for  a  day  or  more.  Where  a  secure  attachment  for  the  gutta- 
percha cannot   be  obtained,  a  plug  of  wood  should  be  inserted 


40  ARTIFICIAL  CROWN-  AND  BRIDOE-WORK. 

temporarily  in  the  root,  and  the  gutta-percha  held  in  position  bj 
being  packed  around  it.  The  root  can  thus  be  exposed  to  the 
border  of  the  alveolar  process  if  desired.  In  bicuspids  and 
molars,  when  decay  extends  up  on  the  cervix  farther  than  will 
the  edge  of  the  artificial  crown  or  the  collar,  the  gums  should 
be  pressed  up  with  gutta-percha,  the  decay  removed,  retain- 
ing-pits  for  a  filling  made,  and  the  cavity  filled  with  amal- 
gam shaped  to  the  contour  of  the  tooth  (Fig.  24).  In  incisors 
and  cuspids,  when  extensive  decay  has  destroyed  a  portion 
of  the  side  of  the  root,  a  tight-fitting  tube  made  of  a  metal  to 
which  amalgam  will  readily  adhere,  and  of  such  size  as  will  ad- 
mit the  pin  of  the  crown,  can  be  inserted  up  the  root-canal  and 
the  upper  end  cemented  in  with  oxyphosphate  and  the  lower 
with  the  amalgam  forming  the  filling  on  the  side  of  the  root.  In 
Fig.  25.  Fig.  26.  Fig.  27. 


Ui 


such  a  case,  the  pin  supporting  the  crown  should  be  tapered  at 
the  end,  and  inserted  in  the  canal  as  deeply  as  possible  beyond 
the  end  of  the  tube.  Additional  strength  is  thus  obtained  ])y 
a  distribution  of  the  leverage  along  the  whole  line  of  the  root. 

When  a  gold  cap-crown  is  to  be  adjusted  on  a  badly  broken- 
down  tooth  or  root,  a  post  of  silver  or  iridio-platinum  wire  should 
be  formed  to  fit  the  root-canals  as  shown  in  Figs,  25,  26,  and  27, 
with  a  piece  of  silver  soldered  crosswise.  The  post  should  then 
be  barbed  and  the  point  first  fastened  in  the  root  with  a  little 
oxyphosphate,  and  the  crown  portion  built  down  about  two-thirds 
of  its  length  with  a  quick-setting  amalgam.  This  when  hard 
should  be  shaped  and  then  roughened  to  furnish  a  better  at- 
tachment for  the  cement  with  which  the  cro^vn  is  set.  Screws 
can  be  used  as  posts  to  support  the  amalgam  if  preferred.  As 
the  artificial  crown  hermetically  covers  all  the  amalgam,  the  ex- 
isting prejudice  against  its  use  cannot  apply  to  this  method. 


PART   IL 


ARTIFICIAL  CROWN-WORK. 


ARTIFICIAL  CROWX-WORK. 

Artificial  cro\vn-work  affords  extensive  facilities  for  restoring 
the  crowns  of  natural  teeth,  and  furnishes  means  of  support  for 
bridge-work. 

Two  general  systems  are  presented — the  porcelain  and  the  gold. 
The  porcelain  system  includes  porcelain  crowns  with  metallic 
attachments,  Avith  or  Avithout  collars,  and  the  gold  system  gold 
crowns  with  porcelain  fronts. 


13 


THE   PORCELAIN    SYSTEM. 


CHAPTER    I. 


PORCELAIN  CROWNS. 


Porcelain  crown-work  is  practiced  by  many  dentists  almost 
exclusively,  excepting  only  the  occasional  insertion  of  a  gold 
cap-crown  on  a  posterior  tooth.  The  reasons  for  this  are,  the 
intricate  character  of  the  construction  of  gold  crowns,  and  the 
objection  to  crowns  with  bands  or  collars. 

The  advocates  of  the  all-porcelain  system  claim  for  it  natural 
appearance,  restoration  of  contour,  strength,  and  cleanliness, 
together  with  simplicity  of  construction  and  easy  adaptation  and 
attachment  to  the  root,  to  which  the  crown  is  hermetically  sealed. 

Porcelain  crowns  are  made  in  two  general  styles.  In  one 
the  crown  is  attached  to  the  root  by  a  pivot,  post,  or  screw, 
one  end  of  which  is  cemented  in  the  root  and  the  other  in  the 
crown.  Such  are  the  Bonwill,  Gates,  Foster,  How,  and  Howland 
crowns.  In  the  other  style,  one  end  of  the  pivot,  or  post,  is 
baked  in  the  porcelain  when  the  crown  is  made,  and  the  other 
end  cemented  into  the  root  when  the  crown  is  adjusted.  The 
Logan,  Brown,  and  new  Richmond  are  of  this  class. 

Special  advantages  are  claimed  for  each  of  these  several  forms 
of  crowns.  A  o-eneral  knowledo;e  of  the  different  methods  is 
therefore  essential  to  determine  the  adaptation  of  each  to  the  re- 
quirements of  a  case. 

The  preparatory  treatment  of  the  roots  respecting  the  process 
of  grinding,  trimming,  and  shaping,  is  nearly  the  same  for  all 
porcelain  crowns.  Exposing  the  end  of  the  root,  by  pressing  the 
44 


THE  BON  WILL    CROWN. 


45 


gum  awaj  from  it  with  gutta-percha  preliminary  to  the  operation, 
will  greatly  assist  the  operator,  by  enabling  him  to  avoid  acci- 
dental laceration  of  the  adjoining  membranes,  and  the  annoyance 
attending  their  bleeding,  besides  permitting  him  to  carefully 
study  the  adjustment  and  cementation  of  the  crown.  Crowns  in 
which  the  post  is  cemented  will  first  be  described. 

THE    BONWILL   CROWN. 

This  crown,  being  one  of  the  first  introduced  in  improved 
porcelain  crown-work,  has  been  very  extensively  used.  The 
process  of  its  adjustment  and  insertion  is  explained  in  a  lengthy 
article  by  its  inventor  and  advocate.  Dr.  W.  G.  A.  Bonwill,  from 
which  the  following  is  presented  : 

"  These  all-porcelain  crowns  have  three  distinctive  features, 
a  concave  or  countersunk  base ;  a  triangular  opening  from  the 
base  to  a  point  at  or  near  the  cutting-edge  of  the  incisore,  the 
base  presenting  to  the  labial  surface  (at  its  upper  portion  this 
groove  is  enlarged) ;  a  peripheral  margin  or  border  resting 
perfectly  flat  on  the  root,  the  concavity  of  the  base  on  the  palatal 
side  being  at  a  much  more  acute  angle  than  on  the  approximal 
sides.  An  anchorage  is  made  in  the  incisors  by  a  depression  or 
undercut  between  the  labial  and  palatal  surfaces,  opening  on  the 
latter.  In  the  bicuspids  and  molars  the  retaining-pits  are  nearer 
the  grinding-surface. 


Fig.  28.      Fig.  29. 


Fig.  30. 


Fig.  31. 


Fig.  32.      Fig.  33.     Fig.  34. 


Fig.  2S. — Sectional  view  of  an  incisor  crown,  from  mesial  side,  showing  the  undercut  at  the 
point  opening  on  palatal  surface,  the  conical  base,  and  the  opening  from  the  same  to  the  retain- 
ing-grooves,  with  the  e.xact  relations. 

Fig.  29.— Palatal  view  of  same  tooth,  a  is  the  external  opening  for  egress  of  alloy  and  for 
packing  around  the  pin.  The  dotted  lines  show  the  recess  or  undercuts  on  the  mesial  and  distal 
sides  and  near  the  point  for  retaining  the  crown,  and  its  relation  with  the  conical  ba.se. 

Fig.  30. — (rrinding-surface  view  of  a  superior  molar  with  the  countersunk  pin-holes  on  the 
buccal  and  palatal  sides. 

Fig.  31. — Same  view  of  an  inferior  molar  with  the  pin-holes  on  the  mesial  and  distal  sides. 

Figs.  32  and  33. — Sectional  view  of  a  molar  and  bicuspid  crown,  showing  the  countersinks 
and  their  relations  with  the  conical  base. 

Fig.  34. — Sectional  view  of  an  incisor  root,  showing  the  ret.aining-cuts  made  by  the  wheel-bur 
shown  in  Fig.  41. 


46 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


"  It  is  not  necessary  that  the  face  of  the  root  should  be  flat ;  it 
may  be  either  concave  or  convex.  The  concave  base  of  the 
crown  prevents  the  amalgam  from  escaping  under  the  heavy 
pressure  exerted  to  force  it  into  position,  and  in  impacting  the 
amalgam  and  expressing  the  mercury.  It  allows  of  a  dense 
body  of  material  around  the  metallic  pin,  giving  the  equivalent 
of  a  pin  the  whole  diameter  of  the  base  of  the  crown.  It 
leaves  no  joint,  the  crown  and  root  being  continuous.  The 
amalgam  is  so  thoroughly  hardened  at  once  by  impaction  in  the 
double  concave  of  crown  and  root  as  to  make  a  very  firm  opera- 
tion. It  prevents  any  possibility  of  the  crown's  twisting  upon 
Fig.  35.         Fig.  37.  Fig.  38.  Fig.  39.  Fig.  40.        Fig.  41. 


Fig.  36. 


Fig.  .3.5.— End  view  of  a  canal  prepared  for  the  improved  combination-metal  pin. 

Fig.  36. — End  view  of  same  canal  as  in  Fig.  35,  prepared  for  a  triangular  pin,  showing  how 
much  more  of  the  mesial  and  distal  surfaces  have  been  cut  away  from  it  than  in  Fig.  'io  for  the 
improved  pin. 

Fig.  37. — Sectional  view  of  an  incisor  crown  and  root,  with  the  improved  pin  in  its  relative 
position  to  each.i  with  the  depressions  made  by  wheel-bur. 

Fig.  .38. — Sectional  view  of  a  superior  molar,  with  the  large  angular  pin  in  palatal  root  and 
two  square  pins  in  the  buccal  roots,  one  being  shorter  and  not  passing  through  the  crown. 

Fig.  39.— Block  of  a  molar  and  bicuspid,  showing  the  countersunk  holes  for  pins  in  the  molar, 
and  the  hole  in  the  mesial  side  of  the  second  bicuspid  where  a  pin  is  alloyed  in  and  set  into  a 
decayed  cavity  in  the  distal  surface  of  the  first  bicuspid,  being  held  upon  the  molar  roots  and 
attached  to  the  bicuspid  by  the  alloy. 

Fig.  40.— Side  and  end  view  of  the  largest  size  angular  combination -metal  pin  with  the 
stamped  serrations.-  The  square  pins  are  without  serrations  and  double-pointed,  made  of  the 
same  metal  and  of  equal  thickness  throughout. 

Fig.  41.— The  smallest-sized  wheel-bur  for  grooving  the  canals  for  anchoring  the  pin  and  alloy. 

1  The  sectional  views  of  the  incisor  and  molar,  giving  the  relative  position  of 
the  pins  in  the  crowns  and  roots,  should  show  pins  of  larger  size.  The  pins  as 
furnished  should  be  filed  down  but  little.  It  is  not  absolutely  necessary  that  so 
many  serrations  should  be  made  in  the  canals  by  the  wheel-bur  for  retaining  the 
amalgam  and  pin  as  are  shown  in  the  sectional  view  of  the  root  of  an  incisor. 
While  no  serrations  are  shown  in  the  roots  of  the  molars,  it  is  understood  that  all 
the  canals  must  have  the  serrations.  The  square  pins  in  the  canals  need  no  serra- 
tions. At  the  point  where  they  occupy  the  countersink  in  the  crowns,  make  two 
or  three  very  slight  cuts  on  the  edges  with  a  sharp  file.    The  ends  can  be  left  blunt. 

2  These  pins  are  now  made  without  serrations.  When  amalgam  is  used  for  se- 
curing them,  they  become  amalgamated  and  firmly  united. 


THE  BON  WILL    CROWN.  47 

the  pin  and  root.  In  the  event  of  fracture  of  the  crown,  the 
convex  surface  of  amalgam  on  the  root  makes  the  substitution 
of  a  new  crown  an  easy  operation.  It  enables  the  operator  to 
fit  the  crown  in  much  less  time ;  it  allows  a  proper  position  to 
be  given  to  the  pin,  with  less  danger  of  fracture  therefrom;  it 
permits  of  a  larger  quantity  of  amalgam  in  the  crown,  and  is 
capable  of  bearing  greater  strain;  it  makes  the  permanent  suc- 
cess of  the  operation  probable,  from  the  fact  that  it  is  absolutely 
jointless,  and  secures  immediate  solidity,  even  while  the  amal- 
gam is  semi-plastic.  These  crowns  are  capable  of  resisting  the 
force  of  biting  or  mastication,  because  they  are  supported  nearly 
to  the  cutting-edge  or  grinding-surface,  the  triangular  opening 
from  the  concave  base  nearly  to  the  cutting-edge  allowing  the 
pin  to  be  imbedded  in  the  labial  face  of  the  crown  where  there  is 
the  greatest  amount  of  porcelain. 

"  The  amalgam  to  be  used  as  the  medium  of  union  must  set 
quickly  and  l)e  very  hard.  Thus  far  I  have  found  nothing  better 
than  the  alloys  I  have  specially  prepared  for  this  line  of  work, 
and,  though  they  are  costly,  the  superior  results  obtained  by 
their  use  amply  repay  the  cost.  I  use  ISTo.  1  generally.  If  mixed 
tliick,  it  will  set  so  quickly  that  the  operator  must  work  rapidly 
to  prevent  its  being  wasted.  In  incisor  cases  I  use  No.  3  at  the 
gum  line,  and  make  a  close  joint. 

"  The  simple  device  which  I  have  called  an  adjuster^  is  a  very 
useful  adjunct  in  the  operation.  It  requires  considerable  force 
to  set  one  of  these  crowns  according  to  directions, — a  force  which 
cannot  be  applied  with  a  mallet  without  danger  of  loosening  or 
displacing  the  crown.  Steady  pressure  with  slight  rotation  will 
carry  the  crown  into  place,  if  the  amalgam  is  not  too  hard  or 
there  is  not  too  much  of  it.  I  would  advise  you  not  to  attempt 
to  set  a  crown  without  one  of  these  adjusters  or  its  equivalent. 

"  A  crown  can  be  mounted  upon  almost  any  root  if  the  alveolar 
process  has  not  been  too  much  absorbed. 

"  It  is  an  advantage  in  every  way  to  take  an  impression  of  the 
root,  either  wnth  plaster  or  modeling  composition,  to  get  the  size 
and  shape  of  the  crown.  The  articulation  b}-  a  bite  in  wax  is 
equally  important. 

^  For  description,  see  article  on  "  Cementation." 


48  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

"  If  the  patient  exposes  the  gums  much  in  speaking  or  smihng, 
the  root  may  be  cut  down  with  the  bur  or  corundum-wheel  be- 
yond the  free  edge  to  conceal  the  joint.  With  bicuspids  and 
molars  it  is  not  necessary  to  go  below  the  gum ;  a  joint  well 
made  will  not  be  observed,  and  the  strength  of  the  root  will  be 
preserved.  If  the  root  is  decayed  below  the  gum,  after  removing 
the  softened  parts,  fill  it  with  alloy ;  if  it  be  split  or  have  very 
thin  walls,  a  platinum  band  can  be  made  separate  from  the 
crown.  This  will  seldom  be  necessary,  as  the  pin,  anchored 
high  up  in  the  root,  will  be  its  equivalent. 

"  In  preparing  the  canal,  use  first  a  small-sized,  spear-shaped 
drill,  carefully  following  the  natural  channel.  Then  follow  with 
a  larger  one,  taking  care  not  to  cut  through  the  root  near  the 
apex.  On  the  mesial  and  distal  sides  cutaway  but  little,  as  there 
is  where  fractures  are  most  liable  to  occur.  The  canal  can  be 
very  tapering  and  yet  hold  the  pin,  if  the  undercuts  or  grooves 
are  well  made  all  along  the  walls  from  the  apex  out.  There 
need  be  but  very  little  space  around  the  pin.  The  mouth  of  the 
root  should  be  countersunk  the  same  as  the  base  of  the  crown, 
in  order  that  the  amalgam  may  extend  to  its  very  edge,  leaving 
no  dentine  exposed.  The  smallest-sized  wheel-bur  may  be  used 
to  make  an  interrupted  female  thread  at  various  points  along  the 
canal  to  hold  the  amalgam.  By  all  means  save  all  the  walls  of 
the  root  possible.  The  face  of  the  root  may  be  fiat  or  concave, 
according  to  indications.     In  most  cases  it  had  better  be  fiat. 

"  The  crown  to  be  inserted  should  be  inspected  closely,  as  the 
retaining  undercut  in  the  incisors  and  the  depressions  in  the  bi- 
cuspids and  molars  may  not  be  well  defined.  If  not,  the  crowns 
are  Hable  to  work  loose.  If  the  base  has  been  ground  off"  in  fit- 
ting, the  edges  should  be  beveled  again  to  a  fine  margin  with  a 
corundum-point.  The  crown  should  be  fitted  to  the  root  in 
the  mouth,  not  to  the  plaster  cast.  The  articulation  should  be 
clear,  to  avoid  displacement.  The  pin  should  be  as  large  as  the 
previously  prepared  canal  will  admit.  The  pin  must  in  every 
case  be  fitted,  and  in  fitting  it  file  only  on  the  plain  sides.  The 
serrations  in  the  large  pins  need  not  be  touched.  Leave  the  end 
sharp,  to  offer  the  least  resistance  in  passing  through  the  amal- 
gam.    The  end  of  the  pin  to  be  passed  into  the  crown  needs 


THE  BON  WILL  CROWN.  49 

very  little  alteration.  The  crown  being  open  on  the  palatal  sur- 
face of  the  incisors,  permits  a  blunt-pointed  pin  to  go  up  to  its 
place.  The  niiddle  of  the  pin  should  not  be  interfered  with  if  it 
can  be  avoided.  It  is  well  to  cut  the  pin  a  little  short  for  in- 
cisors, as  it  may  not  get  pushed  entirely  up  in  the  root  through 
the  amalgam.  The  small  square  pins  are  used  in  the  bifurcated 
roots  of  bicuspids  and  in  the  buccal  roots  of  molars.  They  can 
be  sharpened  at  both  ends,  but  the  outer  end  will  not  require  so 
much  sharpening.  The  palatal  roots  of  molars  will  generally 
take  one  of  the  largest  thick  pins,  with  one  square  pin  in  the 
largest  and  most  accessible  buccal  root.  Each  canal  should  have 
a  pin,  if  the  canal  can  be  reached  and  properly  prepared  to  receive 
it,  even  though  the  pin  has  to  be  so  short  as  not  to  pass  through  the 
hole  in  the  crown.  If  it  enters  the  countersunk  base  it  will  sup- 
port the  root.  The  lower  molars  will  require  two  of  the  largest- 
sized  thin  pins.  As  the  support  of  the  root  is  dependent  upon 
the  size  of  the  pin  and  the  depth  to  which  it  is  inserted,  the 
single-rooted  teeth  should  have  the  very  largest  thick  pin.  If  the 
root  is  thin  on  the  mesial  and  distal  sides,  the  thin,  angular  pin 
is  to  be  preferred.  When  the  pin  is  thoroughly  set  it  is  hard  to 
fracture  the  root.  The  crown  should  go  on  easily  and  correctly 
over  the  pin,  special  note  being  taken  of  the  position  of  the 
latter  in  the  canal,  so  that  it  mav  be  returned  at  the  same  anffle. 
Ordinarily  these  large  pins  do  not  have  to  be  bent.  If  necessary, 
it  had  better  be  done  with  a  hammer,  and  before  the  mercurv 
touches  them.  The  pin  should  have  free  movement  in  both  root 
and  crown.  Should  it  be  discovered  that  the  pin  is  too  long  after 
it  has  been  packed  in  the  root,  it  can  be  cut  off  with  sharp  for- 
ceps, pressing  them  up  against  the  pin  to  prevent  displacement. 
It  can  be  sharpened  subsequently  with  the  corundum-wheel. 

"  To  insure  an  amalgamation  of  the  pin  with  the  tilling,  brighten 
the  surface  of  the  former  before  inserting.  In  the  buccal  roots 
of  molars  the  pins  need  not  be  inserted  more  than  a  quarter  of 
an  inch,  or  even  less,  in  some  cases. 

"The  roots,  crown,  and  pins  being  in  readiness  and  arranged 
on  the  table,  so  that  no  mistake  may  occur  from  getting  the  pin 
in  the  wrong  position,  and  the  appliances  necessary  for  the  opera- 
tion being  at  hand,  the  alloy  preferred  should  be  mixed  a  little 

4 


50  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

thinner  than  if  intended  for  a  filhng,  especially  where  the  root 
has  a  long  canal.  The  shorter  the  canal,  the  thicker  the  amal- 
gam may  be  mixed.  Mix  only  enough  at  one  time  for  one  root. 
Put  enough  amalgam  in  the  canal  to  nearly  fill  it,  but  do  not 
pack  it ;  force  a  steel  pin  made  for  the  purpose,  of  about  the 
same  size  as  the  pin,  to  make  way  for  the  easier  insertion  of  the 
latter.  Then  grasp  the  pin  with  suitable  forceps,  and  carefully 
but  steadily  press  it  up  to  its  destination.  If  you  cannot  suc- 
ceed in  doing  so,  remove  it,  and  again  use  the  steel  pin.  When 
in  place,  use  an  instrument  with  a  point  small  enough  to  pass 
between  the  pin  and  the  root,  and  pack  by  tamping  the  amalgam 
around  it.  A  piece  of  bibulous  paper  placed  over  the  point  of 
the  instrument  will  assist  materially  in  carrying  the  amalgam 
before  it.  Before  the  amalgam  has  become  too  hard,  replace  the 
crown  to  determine  if  the  pin  is  in  proper  position ;  if  not,  it 
can  be  crowded  to  one  side  or  the  other  with  the  tamping-tool. 
Should  the  pin  be  found  to  be  rather  long,  it  can  be  ground  off 
with  the  corundum-wheel,  holding  it  meanwhile  with  the  forceps. 
ISTo  attempt  should  be  made  to  bend  the  pin  after  it  has  been 
amalgamated,  for  fear  of  breaking  it.  If  any  amalgam  has  been 
left,  and  it  is  still  plastic,  it  may  be  packed  around  the  pin  at  the 
base  of  the  root,  using  the  bibulous  paper  as  before  directed.  If 
not,  mix  again  to  complete  the  operation.  Bank  up  the  amalgam 
on  the  root  high  enough  to  fill  the  base  of  the  crown.  The  crown 
should  now  be  tried  on,  and  forced  home  with  an  adjuster 
adapted  to  the  case,  removing  the  surplus  amalgam  if  too  nmch, 
or  adding  if  not  enough.  Remove  and  dry  the  crown,  and  fill 
up  simply  the  undercut  cavity  near  the  cutting-edge  if  an  incisor, 
or  the  depressions  in  the  crowns  of  bicuspids  or  molars,  allowing 
a  very  little  to  extend  into  the  cervical  base.  JSTow  force  it  home 
with  the  adjuster.  Free  mercury  will  be  squeezed  out  on  the 
palatal  surface,  which  should  be  wiped  off.  Now  hold  the  crown 
in  place  with  the  fingers,  with  the  bibulous  paper  under  the 
tamping-instrument,  and  consolidate  the  amalgam  around  the 
point  of  the  pin  in  the  crown,  absorbing  any  free  mercury  which 
appears  there.  The  excess  of  alloy  at  the  joint  must  now  be 
removed,  care  being  taken  to  press  the  crown  up  while  this  is 
being  done.     The  amalgam  packed  around  the  pin  in  the  crown 


THE  HOW  CROWNS  AND  METHODS.  51 

OH  the  palcital  side  should  be  as  stiff  as  may  be  to  work  readily. 
It  is  well  to  leave  over  some  of  the  first  mixins^  for  holdino-  the 
pin,  and  this  will  be  about  right  for  consolidating  about  this 
point. 

"  If  in  a  bicuspid  or  molar  crown  the  pin  should  come  so  far 
through  as  to  interfere  with  articulation,  it  may  be  ground  ofi 
with  the  corundum-wheel  while  the  crown  is  firmly  held. 

"  The  case  can  now  be  dismissed,  with  directions  for  the  patient 
to  return  the  next  day,  in  order  to  make  sure  that  the  articula- 
tion is  correct  and  to  dress  off"  the  joint  between  the  crown  and 
root,  which  may  be  done  with  a  small  round-headed  bur. 

"•  There  are  some  cases  in  which  the  root  cannot  be  filled  with 
anything;  if  in  a  molar,  the  pulp-chamber  can  be  relied  upon  to 
hold  a  headed  pin  or  pins.  When  a  tap-hole  is  required  in  the 
root  it  can  be  made  low  down  and  at  an  acute  angle,  and  the 
amalgam  packed  around  the  root-canal  above  the  tap. 

"  Should  an  artificial  crown  be  broken,  another  can  easily  be 
substituted,  by  burring  off  any  excess  of  amalgam,  and  using 
fresh  amalgam,  mixed  thin,  to  allow  of  ready  adjustment. 
-    "  Lower  incisor  roots,  which  have  hitherto  been  abandoned  to 
tlie  forceps,  can  be  crowned  by  this  process. 

"  Two  crowns  can  be  inserted  on  the  root  of  one  large  molar 
with  the  assistance  of  the  decayed  approximal  surface  of  an 
adjacent  tooth  (see  Fig.  39)." 

THE    HOW    CROWNS    AND    METHODS. 

These  crowns  are  the  invention  of  Dr.  W.  Storer  How.  There 
are  two  styles, — four-pin  crowns  for  incisors,  cuspids,  and  bicus- 
pids, and  porcelain  dovetail  crowns  for  bicuspids  and  molars.  Each 
form  embraces  some  novel  features.  Dr.  How's  methods,  being 
general  in  application,  are  used  in  inserting  other  forms  of  crowns. 

The  following  are  Dr.  How's  descriptions  and  illustrations  of 
his  methods  and  crowns  : 

"  The  Four-Pin  Crown. — The  difficulties  and  uncertainties  in 
mounting  artificial  tooth-crowns  on  roots,  by  either  old  or  new 
methods,  led  me  to  a  careful  study  of  the  problem,  and  resulted 
in  a  nearly  simultaneous  devising  of  several  new  forms  of 
crowns  and  appliances  for  setting  them,  as  well  as  a  perfected 


52 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


Fig.  42.     Fro.  43.     Fig.  46.       Fig.  47.     Fig.  48.     Fig.  49. 


method  of  performing  the  operation  of  fixing  a  peculiar  screw- 
post  (Fig.  42)  in  a  root,  and  also  a  novel  process  of  attaching 
Fig  44  ^^^®  crown  to  the  post.     At  present  I  will  describe  -p^Q  45 
simply  the  four-pin  crown  (Fig.  43)  and  the  suc- 
cessive steps  to  be  taken  in  mounting  it. 
I  "  1.  When  the  root  is  in  proper  condition  for 

mounting,  measure  the  depth  of  the  canal  by 
means  of  the  canal-plugger  and  its  flexible  gauge 
(Fig.  44),  and  fill  the  canal  at  and  a  short  distance 
from  the  apex  of  the  root,  keeping  the  gauge 
at  position  to  show  the  full  length  of  the  canal  and 
also  the  distance  to  which  it  has  been  tilled. 

"  2.  Cut  ofii'the  root-crown  with  excising  forceps 
and  a  round  file,  down  to  the  gum  margin,  and  with 
barrel  bur  ISTo.  241  cut  the  labial  part  of  the  root 
fairly  under  the  gum  without  wounding  it. 


"  3.  Set  gauge  on  a  Gates  drill  (Fig.  45)  to  one- 
half  the  gauged  depth  of  the  canal,  and  drill  to 
that  depth. 

"  4.  Set  the  twist  drill  in  its  chuck  (Fig.  46)  to 
project  the  same  length  as  the  Gates  drill,  and  drill 
the  root  to  exactly  that  depth. 

"  5.  Enlarge  the  mouth  of  tlio  canal  one-sixteenth 
of  an  inch  deep  all  around  to  near  the  margin  of  the  r 
as  shown  in  Fig.  47,  using  square-end  fissure-bur  No. 
and  then  with  oval,  No.  94,  undercut  a  groove  lingually  an 
the  sides. 


H  < 


^  I 

oot, 

59, 

d  at 


THE  HOW  CROWNS  AND  METHODS. 


58 


"  6.  If  the  rubber-dam  is  to  be  used  for  a  gold  or  plastic 
backing,  put  it  now  over  the  root  with  Hunter's  root-clamp, 
also  over  the  adjacent  teeth,  and  thoroughly  dry  the  canal. 

"  7.  Set  the  tap  in  its  chuck  (Fig.  48)  a  trifle  less  in  length 
than  the  drill,  oil  the  tap  and  carefully  tap  the  root  to  the  gauged 
depth. 

"  8.  Insert  the  post  in  its  chuck  (Fig,  49)  to  the  exact  gauge 
of  the  tap,  and  turn  the  thumb-screw  down  hard  on  the  end  of 
the  post,  then  screw  the  post  into  the  root,  release  the  thumb- 
screw, unscrew  the  chuck  a  half-turn,  bend  the  post  until  the 


Fig.  50. 


FiQ.  51. 


Fig.  52. 


Fig.  54. 


Fig.  53. 


Fig.  55. 


chuck  stands  in  center  line  with  the  adjoining  teeth,  and  unscrew 
the  chuck  from  the  post. 

"  9.  Slit  the  rubber  back  from  adjacent  teeth,  tucking  the 
flaps  out  of  the  way,  so  that  the  occlusion  may  be  tried,  the 
post  excised  and  ground  ofl"  until  the  teeth  close  clear  of  the 
post. 

"  10.  Try  the  crown  on  the  post,  and  with  disk  F  grind  the 
rib  between  the  neck  pins  until  the  crown  is  labially  flush  with 
the  root  margin,  using  the  disk  dry  and  cutting  a  little  at  a  time 
until  exactly  flush. 

"  11.  Take  the  crown  and  place  the  mandrel  (Fig.  50)  between 
the  pins  just  as  the  post  is  to  be,  and  with  the  pliers  (Fig.  51) 


54  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

bend  the  pins  carefully  over  the  mandrel,  cutting  off  the  pins  if 
too  long  to  be  pinched  in  on  the  mandrel  at  the  sides,  observing 
that  the  pin  nearest  the  cutting-edge  is  first  to  be  bent  (Fig,  52), 
and  the  opposite  pin  bent  below  it  on  the  mandrel,  and  so  with 
the  others  (Fig.  53). 

"12.  Slip  the  crown  over  the  post,  try  occlusion,  and  with 
the  post-chuck  bend  the  post  until  the  crow^n  is  properly  aligned 
with  the  teeth,  then  with  a  stump  corundum-wheel  JSTo.  3  grind 
the  neck  of  the  crown  to  a  close  labial  fit  with  the  root,  fitting 
only  the  portion  to  be  concealed  by  the  gum,  leaving  narrow 
gaps  at  the  sides  to  be  filled  by  the  backing  between  crown  and 
root  (Fig.  54). 

"  13.  Grind  cutting-edge  for  occlusion  and  relation  to  the 
other  teeth,  and  be  sure  that  the  opposing  tooth  does  not  strike 
the  crown,  the  post,  or  the  pins. 

"  14.  Fix  the  crown  on  the  post  by  pinching  the  pins  into 

Fig.  56.  Pig    57 


the  screw-threads  in  the  post  with  the  special  pliers  for  that 
purpose. 

"  15.  Finally,  pack  the  backing  of  gold,  or  cement,  or  amal- 
gam, or  Wood's  metal,^  or — for  temporary  backing  while  treating 
abscess — gutta-percha,  into  all  the  crevices  around  the  post  and 
behind  and  under  the  pins,  and  between  the  crown  and  the 
root ;  contour  and  finish  thoroughly,  so  that  no  ledge  or  other 
imperfection  can  be  found. 

"  Fig.  55  shows  in  vertical  mid-section,  an  incisor  crown 
mounted  on  a  root;  the  blackened  portions  of  the  backing 
serving  to  define  clearly  the  locking-hold  of  the  backing  on  the 
screw-post,  the  crown-pins,  and  the  root  recess. 

"  Fig.  56  shows  in  perspective  a  cuspid  crown  ready  to  be 

1  Wood's  metal  suggested  by  Prof.  J.  Taft. 


THE  HOW  CROWNS  AND  METHODS.  55 

slipped  over  its  post,  and  also  a  cuspid  crown  ready  for  its  post 
in  the  bicuspid  root,  which  has  its  lingual  cusp  remaining,  and 
Fig.  57  shows  these  crowns  on  their  posts  awaiting  tlie  com- 
pleting or  contour-backing. 

"  When  it  is  desired  to  contour  the  backing  of  a  cuspid  crown 
to  form  an  inner  cusp,  or  to  adapt  a  cuspid  or  incisor  crown  for 
masticating  uses,  the  pins  nvdy  be  twisted  together  over  the  man- 
drel, and  again  twisted  tightly  over  the  post  as  in  Fig.  58 ;  but 
in  some  cases  it  may  be  better  to  bend  the  neck-pins,  as  in  Fig. 
59,  instead  of  twisting  them.  In  all  cases  the  bent  pins  are  to 
be  pinched  quite  hard  over  the  mandrel  and  post,  so  that  the 
serrations  of  the  pliers  will  roughen  the  pins  to  prevent  their 
being  pulled  through  the  backing,  which  should  also  be  carefully 
condensed  around  the  pins  and  post. 

"When  the  root  is  much  decayed,  the  bottom  of  the  cone- 

FiG.  58.  Fig.  59.  Fig.  60. 


shaped  cavity  may  be  drilled  and  tapped  to  the  depth  of  a  six- 
teenth of  an  inch,  and  the  post,  thus  anchored,  may  be  further 
secured  by  cement  in  the  grooved  walls  of  the  cavity  and  around 
the  post  (Fig.  60). 

"  The  screw-posts  are  made  of  crown  metal,  an  alloy  devised 
for  the  purpose  in  order  to  obtain  a  stiff  post  that  will  permit 
the  cutting  of  the  peculiar  and  extremely  accurate  thread  formed 
upon  it,  and  wliich  will  not  amalgamate  or  be  otlierwise  aftected 
by  any  backing-material  that  may  be  used.  Of  course  platinum 
or  platinum  alloyed  with  iridium  may  be  employed  for  posts, 
but  the  crown  metal  is  in  every  way  superior. 

''  There  are  some  cases  of  a  class  which  has  hitherto  presented 
difficulties  that  may  now  be  easily  overcome  b}'  gi-inding  the 


56 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


post  flat  on  the  crown  side  after  it  has  been  set  and  bent  in  the 
root  (Fig.  61),  so  as  to  be  clear  of  the  occluding  tooth;  and  then 
the  crown-pins  may  be  bent  over  the  reduced  post,  the  crown 
fitted  and  ground  to  clear  the  opposing  tooth  (Fig.  62),  and  the 
backing  added  in  completion. 

"A  similar  case,  in  which  the  opposing  tooth  and  a  proper 
alignment  require  an  oblique  bending  of  the  pins,  is  seen  in  Fig. 
63,  while  the  reverse  arrangement  of  parts  is  shown  in  Fig.  64, 
The  crown  is  thus  seen  to  be  adapted  to  a  wide  range  of  adjust- 
ments, because  its  point  of  contact  with  the  root  is  at  the  labial 
portion  of  the  neck,  on  which  as  on  a  hinge  the  crown  may  be 


Fro   61. 


Fig.  62. 


Fig.  63. 


Fig.  G4. 


Fig.  65. 


swung  out  or  in  (Fig.  65,  dotted  lines),  over  an  arc  of  at  least 
sixty  degrees,  at  any  point  of  which  it  may  be  quickly  and  firmly 
fixed.  The  labio-cervical  junction  is  made  just  under  the  gingi- 
val margin,  and  I  usually  interpose  a  thin  layer  of  cement,  amal- 
gam, or  gutta-percha,  or  a  narrow  ribbon  or  several  large  blocks 
of  soft  gold ;  the  joint  always  to  be  made  carefully  smooth,  and 
hid  from  view  under  the  free  margins  of  the  gums." 

The  Porcelain  Dovetail  Tooth-Oroum. — These  crowns  are  de- 
signed for  the  roots  of  bicuspids  and  molars  only,  and  the  process 
of  mounting  them  may  be  very  briefly  described. 

"  Fig.  QQ  shows  the  roots  of  an  inferior  molar  after  the  apical 
portions  have  been  filled,  the  neck  recessed,  the  canals  drilled 
and  tapped,  and  two  How  screw-posts  firmly  fixed  therein,  the 
ends  of  the  posts  having  been  pinched  towards  each  other  by 
means  of  a  pair  of  pliers,  so  that  they  will  go  through  the  cen- 


THE  HOW  CROWNS  AND  METHODS. 


57 


tral  opening  in  the  crown  (Fig.  67).  This  opening  is  of  a  dove- 
tail form,  as  shown  in  cross-section  b}'  Fig.  68,  where  the  crown 
is  seen  in  phice  over  the  posts  on  the  root.  It  is  thus  made 
obvious  that  the  crown  may  be  easily  put  on  and  off  the  root  in 
the  process  of  fitting  the  crown-neck  to  the  root-neck,  and  also 
that,  for  occlusion,  the  crown  may  be  ground  low  on  any  or  all 
sides  without  destroying  the  dovetail  function  of  the  central 
cavity.  When  the  fitting  is  completed,  and  the  crown  cut  so 
short  as  to  be  -gJ^  of  an  inch  distant  from  the  occluding  tooth, 
amalgam  is  packed  into  the  neck  recess,  around  the  posts,  and 
thinly  over  the  cervical  margin  of  the  root,  the  crown  put  in 
place,  and,  with  thumb  pressure,  firmly  seated.  Then  test  the 
occlusion,  and  complete  the  operation  by  packing  amalgam  into 


Fig.  66  Fig.  67.  Fig.  68.  Fig.  69.        Fig.  70.  Fig.  71. 


the  crown  opening,  which  will  permit  the  forcing  of  the  amalgam 
in  all  directions,  to  insure  a  firm  base  for  the  crown,  and  its 
secure  dovetail  attachment  to  the  posts,  as  shown  by  Fig.  68. 

"  The  bicuspid  crown  (Figs.  69  and  70)  is  similar]}^  mounted, 
as  may  be  seen  in  Fig.  71,  cross-section  ;  the  same  crown  and 
root  being  shown  in  contour  by  Fig.  72.  In  some  instances  this 
bicuspid  crown  may,  like  the  Foster  crown,  be  secured  b}'  a 
headed  screw,  as  shown  in  Fig.  73.  The  root  having  been 
drilled  and  tapped  and  recessed,  and  the  crown  properly  fitted 
and  articulated,  the  screw  is  put  through  the  crown,  amalgam 
packed  in  the  crown-groove  and  around  the  screw,  which  is  then 
inserted  in  the  root,  and  the  crown  pressed  hard  into  its  place. 
The  screw  is  then  turned  into  the  position  shown  in  Fig.  73, 
thus  compressing  the  amalgam  or  cement  in  both  recess  and 
groove,  after  which  the  screw-head  may  be  covered  wnth  amal- 
gam, cement,  or  gold,  as  desired. 

"  As  a  preferable  mode,  however,  the  screw-post  may  first  be 


58 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


fixed  in  the  root,  the  crown  adjusted  over  the  post,  amalgam 
packed  on  the  root  and  around  the  post,  the  crown  seated  firmly, 
more  amalgam  packed  in  the  crown  cavity  around  the  post,  and 
then  a  nut  screwed  on  the  post,  as  shown  in  Fig.  74.  In  all  the 
sectional  cuts  cement,  amalgam,  or  gutta-percha  is  to  be  under- 
stood as  filling  the  cavities  in  the  conjoined  roots  and  crowns. 


Fig.  72. 


Fig.  74. 


Fig.  75. 


"  Fig.  75  shows  in  contour  a  dovetailed  crown  mounted  on  a 
superior  molar  root  in  the  manner  shown  by  Fig.  68.  It  is 
obvious  that  the  crown  of  Fig.  68  might  be  ground  quite  down 
to  the  post  ends,  and  yet  be  firmly  held  by  the  dovetail  sides  of 
the  central  cavity." 


Fig.  76. 


in/^nr 


THE  GATES  CROWN. 

The  Gates  crown  has  become  identified  with  the  Bonwill, 
owing  to  its  similarity  (Fig.  76).  It  is  usually  attached  to  the 
root  by  a  metallic  screw  (manufactured  for  the  purpose),  to  which 
amalgam  will  adhere,  instead  of  the  Bonwill  pin  ^  (Fig.  77).    The 

1  Dr.  Gates  originally  used  a  double-ended  oval-shaped  screw.  The  How  screws 
(see  page  52)  manufactured  by  The  S.  S.  White  Dental  Manufacturing  Company 
are  applicable  to  these  crowns. 


THE  FOSTER  AND  ROWLAND  CROWNS. 


59 


Fig. 


screw  is  tirst  inserted  in  the  root  and  the  amalgam  packed  around 
it.  In  nearl}'  all  roots,  at  a  reasonable  distance  up  the  canal,  a 
suitable  place  for  fastening  the  end  of  the  screw  can  be  found. 
Too  much  force  must  not  be  applied  in  its  insertion,  as  a  root  is 
easily  split.  In  bicuspid  and  niolar  crowns  nuts  are  used  on  the 
screws,  which  lit  slots  in  the  grinding-sui-face  of  the  porcelain. 
They  are  screwed  into  the  amalgam  or  cement,  and  covered  with 
it  in  the  process  of  cementation  of  the  crown. 

When  it  is  desirable  or  necessary  to  construct  a  screw 
for  a  special  case,  it  should  be  made  of  iridio-platinum 
wire  (as  this  alloy,  being  hard,  will  well  maintain  the 
edge  of  the  thread).  Gold  is  unsuitable,  owing  to  the 
action  upon  it  of  the  mercury  in  the  amalgam,  even 
though  the  amalgam  is  used  "  dry." 

In  forming  a  screw  a  coarse-thread  screw-plate  should  be  used. 
The  threads  of  most  screws  are  cut  too  fine. 

THE    FOSTER    CROWN. 

The  Foster  erown  (Fig.  78),  which  in  general  form  is  similar 
to  a  crown  introduced  by  Dr.  H.  Lawrence,  of  Philadelphia,  in 
1849,  also  resembles  the  Bonwill,  but  has  less  concavity  at  the 
base.  The  crown  is  attached  to  the  root  by  a  headed  screw  or  a 
screw  with  a  nut  (Fig.  79),  instead  of  the  Bonwill  pin. 

Fig.  78.  Fig.  79. 


The  How  screws  and  instruments  (Fig.  80)  are  best  adapted 
for  use  with  these  crowns. 

THE    HOWLAND   CROWN. 

This  crown,  which  is  similar  in  principle  to  one  originally 
introduced  by  Dr.  C.  TI.  Mack,  was  devised  by  Dr.  S.  F.  How- 
land.  It  is  attached  like  the  TIow  dovetail  crown,  with  screws 
that  are  first  inserted  in  the  root.  It  is  used  oidy  on  bicuspid  and 
molar  roots,  and  consists  of  a  hollow  porcelain  crown,  with  a 
cavity  in  the  crown  sufficiently  large  to  admit  the  screw  or  pins, 
and,  when  necessary,  a  small  })ortion  of  the  root  (Fig.  81). 


60 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


The  method  of  setting  this  crown,  as  described  by  Dr.  How- 
land,  is  to  shorten  the  root  even  with  the  gum  with  a  stump  file; 
Fig.  80.   fit  the  crown  to  the  root;  enlarge  the  root-canal  so  that  a 
I  threaded  pin  of  proper  size  will  pass  in  easily,  partially 

fill  the  canal  with  zinc  phosphate,  and  press  the  pin  to 
its  place  with  pliers.  The  crown  should  then  be  filled 
with  zinc  phosphate  and  pressed  to  its  place,  care 
I  being  taken  to  hold  it  in  position  until  the  cement 
"  sets  (Fig.  82).  If  any  operator  distrusts  the  ability  of 
zinc  phosphate  to  make  a  perfect  joint,  a  small  quantity 
of  silver  amalgam  or  gutta- 
percha can  be  used  to  advan- 


FiQ.  81.       Fig.  82. 


Fig 


tage. 


This  crown  is  strong,  and 

during    its    test    of    several 

years   none  have  broken  so 

far  as  known.     The  mode  of 

fastening  is  strong,  and  has 
the  advantage  of  two  pins  when  set  on  a  bicuspid  having  two  root- 
canals.  It  is  simple,  and  when  set — no  metal  being  in  sight — it 
is  a  perfect  imitation  of  the  natural  tooth  (Fig.  83). 

THE    LOGAN,    BROWN,    AND    NEW    RICHMOND    CROWNS. 

These  crowns  have  their  platinum  posts  or  pins  baked  in  the 
body  of  the  porcelain.     In  the  Logan  crown  the  base  is  made 
Fig.  84.  Fig.  85.  Fig.  86.  Fig.  87. 


concave,  to  facilitate  its  adjustment  to  the  end  of  the  root,  and 
to  give  the  cement  a  more  reliable  form. 


THE  LOGAN  CROWN. 


61 


The  base  of  the  Brown  crown  is  convex,  and  that  of  the 
new  Eichmond  Y-shaped,  from  mesial  to  distal  side.  The 
preparation  of  a  root  for  one  of  these  crowns  is,  in  general, 
sihiilar  to  that  for  the  Bonwill  crown.  The  root-canal  is  en- 
larged, and  sliaped  so  that  the  post,  if  possible,  at  least  at  its 
point,  will  fit  tightly.  Gutta-percha  or  oxyphosphate  is  used  for 
cementing  in  preference  to  amalgam. 


Pig.  88 


Fig.  89. 


Fig.  90.       Fig.  91. 


The  Lixidii  Crnirii. — The  Logan  crown,  now  so  extensively 
used,  is  the  invention  of  Dr.  M.  L.  Logan.  The  method  of 
mounting  is  explained  in  all  its  details  in  the  following  article 
by  Dr.  W.  S.  How  : 

"  Fig.  84  shows  a  superior  right  central  root,  an  end  appear- 

Fig.  n2.  Fig.  93.  Fig.  94.  Fig.  95. 


ance  of  the  same,  and  a  Logan  crown,  front  view.  Fig.  85  ex- 
hibits, at  a  right  angle  to  the  plane  of  the  first  figure,  the  same 
root,  its  end,  and  the  Logan  crown,  side  view.  In  both  figures 
the  root-canal  is  supposed  to  have  been  first  drilled  to  a  gauged 
depth  with  an  engine  twist-drill.  No.  154,  and  then  enlarged  by 
means  of  a  fissure-bur,  No.  70,  to  the  tapering  form  shown ;  the 
walls  being  subsequently  grooved  with  an  an  oval  bur,  No.  90. 


62 


ARTIFICIAL  CROWN-  AND  BRIDGE- WORK. 


The  enlarged  section,  Fig.  86,  shows  the  crown  adjusted  on  the 
root  by  means  of  cement  or  gutta-percha,  which  surrounds  the 
post  and  tills  all  the  spaces  in  the  root  and  crown.  Fig.  87 
shows  the  completed  crown.     Fig.  88  exhibits  a  bifurcated  bictis- 


FiG.  96. 


Fig.  97. 


Fig.  98. 


Fig.  99. 


Fig.  100. 


picl  root,  its  end  appearance,  and  a  Logan  crown  adjusted 
to  the  root.  Fig.  89  illustrates  the  best  manner  of  bend- 
ing the  post.  Fig.  90  shows  a  split  post,  and  its  adapta- 
tion to  a  bifurcated  bicuspid  root  is  seen  in  Fig.  91. 
Figs.  92  and  93  exhibit  the  mode  of  mounting  the  Logan  crown 
on  a  superior  molar  root,  and  Figs.  94  and  95  the  same  crown 
in  its  relations  to  an  inferior  molar  root. 

"  The  preceding  figures  clearly  present  to  the  mind's  eye  of  the 
expert  dentist  the  essential  features  of  the  Logan  crown  and  the 
method  of  mounting  it. 

"  The  details  are  as  follows :  In  every  instance  where  a  root 
is  deemed  ready  to  receive  its  filling,  it  should  first  be  measured 
through  its  canal  from  the  cervical  opening  to  the  apical  foramen, 
and  this  may  be  accurately  done  with  a  gauge  adjustable  on  a 
delicate  canal-explorer  (Fig.  96).  The  same  device  serves  to 
measure  the  distance  from  the  apex  to  which  the  canal  should 
then  be  filled  (Fig.  97).  It  also  gauges  the  depth  to  which  the 
drill  may  be  carried.  The  proper  degree  of  enlargement  from  the 
bottom  of  the  drilled  hole  will,  of  course,  depend  on  the  observed 
size  and  character  of  the  root.  Every  dentist  should  familiarize 
himself  with  generic  tooth-forms,  so  that  when  the  length  of  an 
incisor,  cuspid,  or  other  tooth-root  is  known,  he  can  so  nearly 
determine  its  hidden  outlines  as  to  form  with  precision  a  corre- 


THE  LOO  AN  CROWy. 


63- 


Fig.  102. 


sponding  enlargement  of  the  root-eanal,  such  as  is  shown  by  the 
several  cuts.  For  preparing  the  roots,  the  Ottolengui  root- 
reamers  (Fig.  101)  and  facers  (Fig.  102)  are  very  desirable  instru- 
ments. The  reamers  are  made  in  three  sizes  to  correspond  with 
the  Logan  pins.  With  a  root-reamer  of  the  appropriate  size, 
the  root-canal  is  enlarged  to  tit  the  pin  along  its  whole  length, 
and  so  hold  the  crown  tirmly  iixlependentb/  of  the  cement.  With 
a  root-tacer  a  labial  slope  is  given  to  the  root-end,  so  that  the 
crown  neck  shall  lit  under  the  edge  of  the  gum.  Fig.  103 
shows  the  method  and  its  result,  and  the  cross-section  shows 
how  the  cement  encases  the  pin.  The  suitable  preparation  of 
Fig.  101.  the  bifurcated  roots  of  some 
<  A  bicuspids  and  of  all  the  mo- 
lars is  a  matter  involving 
difficulties  of  an  unusual 
character  and  requiring  good 
iudo-ment.  The  feasibilitv  of 
splitting  the  post  of  a  Logan 
crown  to  adapt  it  to  the 
bifurcated  root  of  a  bicus- 
pid is  shown  hy  Figs.  90  ami 
This  example  directs  attention  to 
the  peculiar  shape  of  the  post,  in  which 
there  is  effected  such  a  distribution  ut 
the  metal  that  its  greatest  strength  is 
in  the  line  of  the  greatest  stress  that 
will  in  use  be  brought  to  bear  on  the  crown,  while  the  least 
metal  is  found  at  the  point  of  the  least  strain ;  the  apphed  part 
of  the  post  being  in  outline  nearly  correspondent  to  that  of  the 
root  itself.  The  root-canal  is  likewise  conformably  enlarged  to 
receive  the  largest  and  stiffest  post  which  the  size  and  shape  of 
the  root  will  permit. 

"  The  fitting  of  a  Logan  crown  to  a  root  may  be  done  with  a 
wet  stump-wheel  in  the  engine  hand-piece.  Using  a  safe-side 
crown  corundum-wheel  (Fig.  104),  in  the  same  manner,  affords 
the  greatest  facility  for  the  slight  touches  required  to  abrade  the 
thin  cervical  borders  of  the  crown,  which  may  by  this  means  be 
done  without  encroachment  on  the  post. 


91 


D 


0 


64 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


"  By  the  old  method  of  adapting  pivot-teeth  to  roots,  the 
close  fitting  of  the  crown  precluded  the  use  of  a  plastic  packing, 
because  its  thinness  over  the  surface  of  the  joint  made  the  pack- 
ing liable  to  break  loose  under  the  shock  and  strain  of  use. 
The  recess  in  the  Logan  crown  obviates  this  defect  by  providing 
a  receptacle  for  a  considerable  interior  body  of  cement  that  will 
be  deep  enough  to  be  self-sustaining  internally,  and  yet  allow 
the  peripheral  portions  of  the  root  and  crown  to  approach  each 
other  so  closely  that,  though  only  a  film  of  packing  remain,  it 
will  still  be  strong  enough  to  insure  the  persistent  tightness  of 

Fig.  103 


the  joint.     This  annular  boss  if  formed  of  amalgam  also  adds 
strength  in  some  cases  to  the  mount. 

"  When  enough  of  the  natural  crown  remains,  it  is  well  to 
leave  standing  some  of  the  palatal  portion,  and  cut  the  root 
under  the  gum  margin  at  only  the  labial  part,  as  shown  by 
Fig.  98.  The  safe-side  crown  Avheel  is  especially  useful  in  such 
cases  (Fig.  105).  Thus  the  lal)ial  joining  of  the  root  and  crown 
will  be  concealed,  and  the  other  parts  of  the  joint  will  be  acces- 
sible for  finishing  and  keeping  clean  (Fig.  99).  The  Logan 
crown  may  be  ground  until  a  large  part  shall  have  been  removed 
for  ada|)tation  to  the  occluding  tooth  or  teeth  without  seriously 
impairing  its   strength   (Fig.  100).      This    crown  also  in  such 


THE  BRO  WN  CRO  WN. 


65 


cases  maintains  the  translneency  which  is  one  of  its  peculiar  ex- 
cellences, owing  to  its  solid  porcelain  body,  and  the  absence  of 
a  metallic  backing  or  an  interior  largely  lilkMl  witli  cement  or 
amalgam. 

"•  The  distal  buccal  root  of  the  natural  superior  molar  is  nearly 
always  too  small  to  receive  a  post  of  any  useful  diameter,  and 
therefore  the  Logan  superior  molar  crown  has  Init  two  posts, 
which  like  those  of  the  inferior  molar  crown  are  square,  and 
thus  may  ])e  easily  l)arbed,  as  may  also  the  riblied  posts  of  the 
crowns  for  the  anterior  tooth-roots.  These  posts  are  large  enough 
in  all  the  Logan  crowns  to  answer  in  any  given  case,  and  can  of 
course  l)e  easily  reduced  to  suit  thin  or  short  roots. 

"Any  of  the  cements  or  amalgams  may  be  used  in  fixing  these 
crowns,  but  good  gutta-percha,  softened  at  a  low  heat  and  (piickly 


Fig.  104. 


Fig.  105. 


wraj)j)ed  around  the  heated  crown-post,  which  is  at  once  seated 
in  the  root,  forms  the  best  mounting  medium,  and  has  the  great 
ad\"antagc  of  permitting  a  readjustment,  or,  if  need  be,  the  ready 
removal  of  the  crown  by  grasping  it  with  a  \n\\v  of  liot  jihers  or 
forceps,  and  holding  it  until  the  gutta-i)ercha  is  sutiieiently 
softened." 

The  Broir),  Croirn. — Fig.  106  is  a  lateral  view  of  a  porcelain 
crown,  with  an  iridio-platinum  pin  baked  in  position,  invented  l)y 
Dr.  E.  Parnily  Brown.  The  pin  has  great  strength  at  the  neck 
of  the  tooth,  where  the  strain  is  heaviest,  and  this  strength  is  fur- 
ther increased  by  extending  the  porcelain  up  on  to  the  pin. 

Fig.  107  is  a  front  view  of  the  same  crown,  showing  by  the 

5 


66 


ARTIFICIAL  CROWN-  AND  BRIDGE- WORK. 


clotted  lines  the  shape  of  the  phi  and  the  position  which  it  occu- 
pies in  the  crown. 

The  pin  is  flattened  laterally,  a  conformation  which  affords  a 
strong  hold  in  th<^  porcelain  without  permitting  the  pin  to  ap- 
proach the  surface  in  thin  teeth,  while  it  also  permits  alteration 
of  the  palatal  surface  of  the  crown  in  a  close  "  bite  "  without 
risk  of  weakening  the  body. 

Fig,  108  is  a  view  of  the  bicuspid  crown,  in  which  a  pin  is  pro- 
vided for  each  root  of  two-rooted  bicuspids. 

Fig.  109  is  a  view  of  a  bicuspid  crown  with  the  two  pins 
pressed  together,  forming  a  single  pin  of  great  strength  for  a 
tooth  with  only  one  root. 

The  double  pin  in  the  bicuspids  prevents  the  gradual  loosen- 
ing of  the  crown  by  the  rotary  movement  of  the  jaws  in  mastica- 
tion, which,  acting  on  the  two  cusps,  exerts  such  leverage  as  to 


Fig.  106. 


Fig.  107. 


Fig.  1 


Fig.  109. 


sometimes  turn  and  break  down  ordinary  crowns  where  only  one 
pin  is  used. 

The  roots  are  ground  concave  to  lit  the  crowns  with  corundum- 
points  or  a  Willard  countersink  bur,  and  close  joints  are  made 
well  under  the  gum,  the  pins  being  set  with  oxyphosphate 
cement.  The  canal  should  be  enlarged  enough  only  to  admit 
the  pin,  which  should  fit  snugly  throughout  its  entire  length,  the 
better  to  distribute  the  leverage  exerted  by  the  crown,  and  thus 
directly  to  increase  the  strength  of  the  attachment.  (For  process 
of  cementation,  see  article  on  "Insertion  and  Cementation.") 

The  Neiu  Richrnond  Crovm. — To  illustrate  and  describe  the 
method  of  mounting  this  crown,  a  superior  left  central  incisor 
root  will  serve  as  a  ty]»ical  case,  and  its  projecting  end  is  to  be 
shaped  as  seen  in  Figs.  110  and  111.  This  can  be  rapidly  done 
with  a  narrow  safe-sided  flat  or  square  file,  the  angles  of  the 


THE  NEW  RICHMOND  CROWN. 


67 


slopes  ])ciiig  such  that  the  gum  on  the  hiMal  and  pahital  as[ieets 
will  not  interfere  with  nor  l)e  disturhed  hv  this  preliuiinarv  work, 
as  the  root  end  is  not,  in  this  operation,  to  he  cut  quite  down  to 
the  gum.  An  Ottolengui  root-reamer  jS^o.  2  is  then  employed  to 
bore  out  the  root  to  receive  the  crown-pOvSt,  which  is  of  the  same 
size  and  shape  as  the  Logan  crown-post  for  a  central  incisor. 

The  sectional  view  (Fig.  112)  sliows  the  relation  of  the  reamer 
to  the  root.  The  new  Richmond  crown  (Fig.  113)  is  then  tried 
on  the  root  (Fig.  114),  and  its  position  relative  to  the  adjacent 
and  occluding  teeth  noted.  If  the  cutting-edge  of  the  crown  is 
to  be  brought  out  for  alignment  with  its  neighbors,  the  root  can 
be  drilled  a  little  deeper,  and  the  reamer  pressed  outward  as  it 
revolves  to  cut  the  lal)ial  wall  of  the  ca\'ity.  Tlie  palatal  yooX- 
slope  must  then  V)e  filed  to  make  the  V  correspond  to  the  changed 
inclination  of  the  crown. 


Fig.  110. 


Fig.   111. 


Fig.   112. 


Thus,  by  alternate  trial  and  reaming  and  tiling,  the  crown 
may  be  fitted  to  the  root  and  adjusted  in  its  relations  until  the 
post  has  a  close,  solid  l^earing  against  the  labial  and  palatal  walls 
of  the  enlarged  pul})-chamber,  and  the  crown-slo[)es  are  se})arated 
from  the  root-sloi)es  by  the  thickness  of  a  sheet  of  heavy  writing- 
paper.  This  space  can  be  accurately  gauged,  and  the  root-slopes 
conformed  to  the  crown-slopes  by  warming  the  crown  and  put- 
ting on  its  slopes  a  little  gutta-percha,  so  that  an  impression  of 
the  root-end  may  be  taken,  and  the  root-slopes  dressed  with  a 
file  until  the  film  of  gutta-percha  proves  to  be  of  equal  thinness 
on  l)oth  slo[>es. 

To  permanently  attach  the  crown.  Dr.  liichmond  usually  takes 
a  thill,  perforated  disk  of  gutta-]ici-cha,  ]iushes  the  post  through 


68 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


it,  warms  the  crown,  presses  it  into  place,  and  when  cooled 
removes  it,  and  with  a  sharp  knife  trims  away  the  gutta- 
percha close  to  the  crown-neck.  He  then  warms  the  crown, 
puts  a  very  little  oxyphosphate  cemient  on  the  post,  and  presses 
the  crown  home.     Fig.  115  shows  the  completed  crown. 

The  obvious  advantages  of  the  device  are  the  readiness  ^^dth 
which  the  slopes  of  the  root-end  may  he  shaped  with  a  file ;  the 
facility  with  which  these  slopes  may  be  given  any  angle  to  set 


Fig.  113. 


Fig.  114. 


Fig.  115. 


Fig.  116. 


the  crown  out  or  in  at  the  base  or  at  the  cutting-edge,  or  to  give 
it  a  t^vist  on  its  axis;  the  certainty  that,  once  adjusted,  the  final 
setting  will  exactly  reproduce  the  adjustment;  the  assurance 
that  in  use  the  crown  "\^'ill  not  be  turned  on  its  axis, — a  most 
common  cause  of  the  loosening  of  artificial  crowns ;  the  firm- 
ness of  its  resistance  to  outward  thrust  in  the  act  of  biting. 
This  is  made  apparent  l)y  Fig.  116,  wherein  it  will  l)e  seen 
that  in  an  outward  movement  the  crown  B  would  rock  upon  A 


Fig.  li: 


Fig.  118. 


Fig.  119. 


as  a  }iiv()t.  The  dotted  line  D  shows  liow  the  crown-slope  is 
resisted  by  the  root-slope,  ^^•hicll  extends  so  far  towards  the 
incisive  edge  that  a  much  firmer  support  is  given  to  the  crown 
than  if  the  resistance  should  be,  as  it  usually  is,  on  the  line  of 
the  ffintj-ival  niaru'in  C. 


REMARKS  ON  THE  USE  OF  PORCELAIN  CROWNS.  69 

For  roots  that  have  liecoiue  wasted  Ix-low  the  gum-surface  it 
is  iu)t  suital)le,  except  in  such  cases  as  are  decayed  under  the 
hd)ial  or  })alatal  o'uni-margin  only,  hut  have  yet  projecting  the 
a}>pr()xirual  portions  of  the  crown  (Fig.  117). 

The  sectional  view  (Fig.  118)  and  the  perspective  plan  views 
(Fig.  119)  illustrate  the  manner  of  mounting  these  crowns  on 
this  class  of  roots.     Tlie  finished  crown  appears  as  in  Fig.  119. 

The  cases  for  which  this  crown  seems  specially  adapted  are 
such  as  have  some  considerable  portion  of  the  natural  crown 
remaining. 

REMARKS    ON    THE    USE   OF   PORCELAIN    CROWNS. 

P(n'celain  crowns  have  some  decided  advantages.  They  are 
especially  useful  in  many  cases  where  an  inexpensive  or  easily 
adjusted  crown  is  recpiired;  or  where  some  pathological  C(in- 
dition  limits  the  probable  duralnlity,  or  permanency,  of  any 
operation.  In  the  insertion  of  porcelain  crowns,  the  removal  of 
the  whole  or  a  part  of  the  natural  crown,  which  could  l)e  uti- 
lized to  some  extent  as  a  foundation  1)y  other  systems,  has  given 
rise  to  various  oljjections.  If  tlie  natural  erown  is  entirely  cut 
away,  the  pin,  or  post,  u[>on  which  almost  the  entire  su}»port  (^f 
the  artificial  crown  is  thrown,  acts  like  a  lever  in  the  root-canal, 
there  being  no  band  or  brace  to  relieve  the  strain.  With  the 
whole  force  of  mastication  bearing  directly  upon  these  puljdess 
roots,  whose  disintegration  is  slowly  but  constantly  progressing, 
the  inevitable  result  can  well  be  conjectured.  Sooner  or  later 
they  are  fractured,  and  their  usefulness  as  a  foundation  ended. 
Then,  again,  if  porcelain  crowns  are  attached  Avith  amalgam, 
the  discoloration  of  the  line  of  union  with  the  root,  if  subse- 
quently exposed,  is  disfiguring.  These  facts,  and  the  lark  of 
strength  incident  to  some  forms  of  construction,  are  the  priiu-i- 
[)al  objections  urged  against  porcelain  crowns  as  ordinarily 
inserted. 


CHAPTER  IL 


PORCELAIN  CROWN  WITH  GOLD  COLLAR  ATTACHMENT. 

A  GOLD  collar,  either  seamles-^  or  soldered,  can  be  used  advan- 
tageously in  combination  witli  many  of  the  porcelain  crowns. 

The  root  having  been  properly  prepared,  a  collar  is  adjusted 
and  adapted  to  it  the  same  as  for  a  gold  collar  crown  (see  page 
'79).  The  porcelain  crown,  the  base  of  which  should  l)e  fully 
as  large  as  the  end  of  the  root,  is  then  ground  even  \^'ith  the 
cervical  walls,  and  fitted  into  the  collar,  which  should  be  trimmed 
and  Ijurnished  to  the  form  of  the  crown.  Enough  of  the  collar 
should  be  trimmed  away  at  the  labial  portion  to  Y)revent  too 
conspicuous  exposure  of  the  gold  (Fig.  120). 

Fig.  124.        Fig.  125. 


Pig.  120. 


Fig.  121. 


Fig.  122. 


Fig.  123. 


This  collar  combination  is  available  in  very  difficult  cases,  as, 
for  instance,  when  a  root  is  decayed  far  beneath  the  gum,  as 
seen  in  Fig.  121. 

Such  an  operation,  when  completed,  would  appear  in  vertical 
section  like  Fig.  122,  and  a  view  in  perspective  would  resemble 
Fig.  123.  The  collar  is  also  very  useful  wherever  the  root  and 
crown  are  not  made  flush  and  smooth  at  every  point,  as,  if  prac- 
ticaT)le,  they  should  always  l)e. 

Dr.  E.  C.  Kirk,  of  Philadelphia,  uses  for  Incuspids  and  molars 
a  Foster  crown  in  combination  with  a  collar  (Fig.  124).  A  collar 
70 


PORCELAIN  CROWN  WITH  GOLD  COLLAR  ATTACHMENT.      71 

is  made,  and,  on  l)eing  fitted  to  the  root,  is  cut  narrow  on  the 
labial  side,  and  left  wide  on  the  linarual,  so  that  it  shall  extend 
nearly  to  the  cusp  of  the  crown  when  finished  (Fig.  125).  (The 
seamless  gold  collars  are  well  suited  for  application  to  this  style 
of  crown.) 

The  crown  selected  should  liave  a  somewhat  greater  circum- 
ference at  the  base  than  the  collar,  so  that  Avhen  ground  down 
somewhat  conically  on  its  lingual  and  approximal  surfaces,  it 
can  V)e  tightly  adjusted  to  the  collar.  If  a  crown  smaller  tlian 
the  collar  is  used,  a  tight  joint  cannot  he  made.  The  screw  is 
fitted  so  that  it  shall  hold  the  crown  in  proper  relations  with  the 
root.  The  screw  and  crown  are  then  removed,  the  parts  dried, 
and  the  root-canal  filled  with  a  slow-setting  ox}^3hosphate  cement, 
mixed  thin.  The  crown  is  then  pressed  into  its  position,  the 
surplus  cement  flowing  through  the  opening  in  the  porcelain 
and  filling  up  any  interstices  around  or  between  the  band,  the 
root,  and  the  crown.  The  screw  is  then  driven  into  position, 
and  when  the  cement  is  set  perfectly  hard  the  head  of  the 
screw  or  the  nut  on  it  is  notched  to  form  a  retaining-pit,  and 
the  countersink  of  the  crown  filled  with  gold. 

Dr.  C.  S.  W.  Baldwin,  of  IS'ew  York  City,  caps  the  root  and 
attaclies  a  Logan  crown  in  the  following  manner. 

First,  the  root  is  shaped,  the  (juter  margin  being  beVL-led 
al)Out  tile  thickness  of  the  gold  used,  to  aftbrd  regular  sides  foi" 
close  ada})tation  of  the  caps.  Then  an  impression  is  taken  and 
a  die  made  in  the  gold  seamless  cap  method.  To  strike  up  the 
cap,  place  Xo.  32  gauge  gold  plate  on  a  cushion  of  lead,  holding 
the  die  firndy  on  the  gold  where  you  wish  to  produce  the  cap, 
and  strike  until  the  recpiired  depth  is  secured  before  remo\'ing  it. 
This  drives  the  gold  and  die  into  the  lead,  forming  a  female  die 
and  a  perfect-fitting  cap  at  once,  in  less  time  than  is  occupied  in 
describing  the  process.  Trim  the  edges  to  fit  the  festoon  of 
the  gum.  and  drill  a  hole  from  the  inner  side  \'ov  the  pin,  leav- 
ing the  raggedness  made  l)y  drilling  to  catch  in  the  cement. 
Place  the  ca})  on  the  root  and  fit  the  }iorcelain  crown  accurately 
to  it  in  the  desired  occlusion  and  position.  A  Logan  erown 
can,  with  little  grinding,  be  made  to  do  good  service  (Fig.  126). 
A  crown  having  the  H-sha[ied  pin,  but  scpiare  on  the  edge,  Hke 


72 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


some  of  the  early  patterns  of  Logan  or  Bonwill  crowns,  would 
reduce  the  thne  of  setting  and  give  best  results.  Having 
polished  the  edges  of  the  cap,  the  crown  may  he  conveniently 
adjusted  as  follows  :  Place  ox^^i^hosphate  cement  in  the  counter- 
sunk portion  of  the  porcelain,  and  in  the  canal  only  enough 
cement,  of  creamy  consistence,  to  fill  it,  as  the  pressure  required 
to  force  out  the  surplus  under  the  edges  of  the  cap  destroys 
many  nicely  adjusted  crowns,  leaving  bulging  irritants  instead 
of  smooth  supports.  If  proper  attention  has  been  given  to 
fitting  crown  and  root,  all  will  come  nicely  to  place,  but  in  some 
cases  of  difficult  adjustment  it  may  be  necessary  to  cement  the 
crown  to  the  cap  before  fastening  the  pin  in  the  root  (Fig.  127). 
Fig.  126.  Fig.  127.  Fig.  128.  Fig    129. 


In  most  cases  the  gold  l)and  will  be  invisible  and  below  the 
free  margin  of  the  gum.  Cases  may  occur  where  the  anterior 
teeth  are  prominent,  and  it  will  be  necessary  to  cut  away  the 
top  of  the  cap  in  front,  allowing  the  porcelain  to  come  directly 
in  contact  with  the  root,  the  band  going  deeper  than  in  ordi- 
nary cases,  which  prevents  the  appearance  of  gold  (Fig.  128). 

Dr.  Bonwill's  \A-An  is  to  cap  the  tooth  with  a  platinum  or  gold 
cap  having  a  slot,  into  which  the  pin  passes  as  it  is  slipped  on 
the  root  (Fig.  129).  Tlie  crown  is  then  tastened  on  with  amal- 
gam in  tlie  usual  manner. 


CHAPTER    III. 


THE  WESTON  CROWN. 


Dr.  Henry  Weston's  method  of  crowning  is  (leseril)ed  by  him 
as  tollows : 

"  This  crown  represents  on  its  hiljial  surface  the  ordinary  phite 
tootli,  tile  hngual  or  })ahital  surface  being  concaved  in  such 
a  manner  as  to  afford  the  hirgest  amount  of  working  room  Avith- 
out  impairing  its  strength  at  any  point.  The  pins  are  so 
imbedded  in  the  thickest  part  of  the  crown  that  it  is  not  hal)le 
to  be  weakened  by  grinding.     Fig.  130  represents  the  crown. 


Fig.  130. 


Fig.  132. 


Fig.  133. 


Fig.  134. 


Fig.  135. 


"  Tlie  pin  is  made  of  hard  platinum  and  iridium,  and  is  spear- 
shaped  and  notclicd  on  both  edges  to  give  tirmness  to  its 
anchorage.  The  b;n'king  is  of  tlie  same  metal  and  strongly 
soldered  to  the  [)in.     Fig.  131  represents  the  pin. 

'"  Tbe  preparation  of  the  root  for  tlie  reception  of  the  crown 
consists  in  the  removal  of  that  part  of  the  tooth  which  is  to 
be  replaced  by  the  porcelain.  Fig.  132  shows  the  root  at  this 
stage. 

"  The  canal  must  be  sufficiently  enlarged  to  allow  space  for 
packing  gold  or  amalgam  securely  about  the  pin,  and  the  sides 
reamed  (Fig.  133). 

''The  grinding  of  the  i-ro\vn  to  tbe  root  re(piires  but  little 
labor,  and  tbe  tittinu'  mav  be  done  directh"  on  tbe  natural   I'oot, 


74  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

or  on  a  cast  taken  after  the  root  has  heen  prepared.  This  must 
always  1;)e  done  T^^th  the  ntmost  neatness  and  precision.  When 
fitting,  the  crown  can  be  hekl  in  position  by  a  cone  of  wax  in- 
serted in  the  root.  Next  comes  the  adjustment  of  the  pin  to  the 
root  of  the  crown.  After  punching  holes  in  the  backlog  to 
receive  the  pins  of  the  porcelain  crown,  bend  the  pin  with  small 
flat-nosed  pliers,  so  that  when  in  its  proper  position  there  shall 
be  a  uniform  space  around  its  entire  surface. 

"  Secure  the  tooth  and  pin  together  with  a  cement  of  resin 
and  wax,  invest  in  plaster  and  sand,  and  solder  with  fine  gold 
solder. 

"  It  has  been  my  practice  of  late  years  when  preparing  the 
root  to  leave  just  a  line  of  enamel  around  its  entire  circumfer- 
ence, thus  securing  a  joint  clear  of  the  free  edge  of  the  gum, 
especially  when  gold  is  used.  If  gold  is  to  be  used  as  the 
attachment,  the  rubber-dam  is  indispensable.  When  amalgam 
or  cement  is  used,  the  rubber-dam  may  be  dispensed  with 
b}'  those  who  prefer  other  methods  of  keeping  out  moisture. 
When  gold  is  to  be  used,  the  root  having  been  pre\dously 
properly  treated,  and  everything  in  readiness  and  the  rubber- 
dam  in  place,  put  upon  the  point  of  the  pin  a  pellet  of  phos- 
phate or  oxychloride  of  zinc,  the  size  of  a  No.  7  or  ISTo.  8  exca- 
vating bur ;  now  press  the  pin  and  crown  carefully  to  their  exact 
position  into  and  upon  the  root,  and  with  a  delicate  but  1)lunt- 
pointed  instrument,  thin  enough  to  reach  the  end  of  the  canal, 
pack  the  cement  firmly  aljout  the  pin.  The  ol^ject  in  using  the 
cement  is  to  secure  the  pin  in  its  place  during  the  first  introduc- 
tion of  the  gold.  By  using  the  hot-air  syringe,  the  cement  will 
harden  in  two  minutes.  Close  the  opening  of  the  canal  al)out 
the  pin  with  a  rope  of  bibulous  paper,  and  attach  the  crown  to 
the  root  and  adjoining  teeth  on  either  side  with  soft  wax;  see 
that  the  joints  are  exact  in  every  particular,  as  after  the  next 
step  mistakes  are  not  easily  remedied. 

"  Paint  the  joint  from  the  labial  side  with  cement  mixed  to 
the  consistence  of  cream.  Cover  the  labial  surfaces  extending 
over  the  cutting-edges  of  the  porcelain  crown  and  adjoining 
teeth  to  the  thickness  of  three-eighths  of  an  inch  with  carefully 
mixed  impression  plaster.     When  hardened,  the  plaster  may  be 


THE   WESTOX  CROWS.  75 

cut  from  the  cuttiiig-edge  of  the  crown,  and  the  wax  and  the 
paper  removed.  Xow  paint  the  pahital  sides  of  the  joint  with 
the  cement  mixed  to  a  cream-like  consistency,  applied  with  flat- 
tened root-canal  plnggers.  Harden  with  hot  air,  and  the  case 
is  ready  for  the  gold. 

"  When  filled  and  finished,  the  exposed  dentine  and  enamel 
are  all  covered  with  eohesive  gold  and  i)oreelain;  the  result  will 
J)e  a  tac-simile  of  Figs.  134  and  135. 

"  If  preferred,  the  cement  in  the  labial  joint  may  l»e  dispensed 
with,  and  the  space  between  the  crown  and  the  root  carefully 
filled  with  gold  after  the  removal  of  the  plaster,  covering  all  of 
the  ex^josed  root  and  showing  only  a  fine  line  of  gold  at  the 
margin  of  the  gum. 

"  Where  amalgam  is  used  exclusively  for  tlie  attachment,  the 
greatest  accuracy  should  be  oljserved  in  the  proper  articulation 
of  the  crown  before  introducing  or  packing  it  and  in  remo^'ing 
carefully  all  excess,  and  the  patient  should  lie  cautioned  against 
bitintr  on  the  crown  until  the  followino-  dav." 


CHAPTER  IV. 

PORCELAIN   CROWNS  WITH  RUBBER  OR  VULCANITE  ATTACH- 

MENT. 


Fig.  136. 


Fig.  136  illustrates  the  formation  of  such  a  crown.  The  root, 
when  prepared,  extends  at  the  palatal  side  a  little  below  the  line 
of  the  gum  (A)  at  the  point  B.  A  plate-tooth 
(C)  is  ground  and  fitted  to  the  root.  An  iridio- 
platinum  post  is  then  fitted  to  the  root,  flattened 
slightly  and  Vjent  at  D,  and  riveted  to  the  tooth. 
The  proper  alignments  of  the  tooth  and  post  to 
the  root  are  then  obtained,  and  they  are  invested 
and  the  jtost  soldered  and  strengthened  at  the 
point  D.  The  backing  is  then  grooved  and 
/  notched  slightly,  wax  applied,  the  crown  ad- 
justed to  the  root,  and  the  wax  shaped  so  as  to 
form  a  foundation  and  overlapping  edge  at  the 
}»alatal  portion  (E).  The  crown  is  then  re- 
moved, invested  in  a  flask,  packed  with  rubber, 
and  vulcanized.  In  trimming  and  finishing, 
the  ruljber  is  allowed  to  form  a  partial  band 
or  collar  around  the  palatal  portion  of  the  wax, 
where  it  will  not  show.  It  is  then  cemented  on  to  the  root  Avith 
oxyphos})hate. 

The  Weston  crown  and  the  four-pin  How  crowns  have  ad- 
vantages over  ordinary  plate-teetli  in  the  construction  of  this 
style  of  work. 


76 


THE    GOLD    SYSTEM. 


CHAPTER  V. 


PORCELAIN   AND   GOLD  CROWN    WITHOUT   A    COLLAR. 


The  root  of  a  cuspid  will  be  taken  as  a  typical  case  to  illustrate 
the  construction  of  this  style  of  crown. 

The  end  of  the  root  is  prepared  the  same  as  for  a  porce- 
lain crown  (Fig.  137).  The  root-canal  is  then  uniforndy  en- 
larged a  reasonable  distance  up,  with  a  drill  Avliicli  will  tightly 
fit  the  opening.     Into  the  canal,  gauging  its  full  diameter,  is 


Fig.  137. 


Fig.  139. 


Fig.  140. 


Fig.  141. 


fitted  a  piece  of  iridio-phitiiitini  ^\'ire,  tapered  off  to  a  point,  so 
that  by  introducing  it  far  up  the  canal  greater  strength  can  l)e 
obtained,  and  the  root  rendered  less  liable  to  longitudinal  fracture 
from  pressure  in  a  f)rward  direction.  A  ]iiece  of  }tlatiiuim 
plate,  a  trifle  larger  than  the  end  of  tlie  root,  of  about  Xo.  30 
U.  S.  standard  gauge,  with  a  hole  ])unt'hed  in  its  center,  is  then 
slipped  on  the  post,  which  it  nuist  fit  tiglitly  (Fig.  138). 

When  the  post  is  adjusted  firndy  in  the  canal,  the  ]tlatimim 
plate  is  pressed  down  on  the  root,  and  burnished  into  the  orifice 


78  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

of  the  canal  around  the  post.  "When  the  post  is  withdrawn  from 
the  root,  the  phitinum  will  adhere  to  it,  if  fitted  closely,  with- 
out the  use  of  wax.  A  particle  of  pure  gold  with  borax  is 
put  in  the  joint,  and  melted  in  the  flame  of  an  alcohol  lamp. 
Barely  enough  gold  should  be  used  to  unite  the  parts.  "When 
soldered,  the  post  and  cap  are  again  adjusted  in  the  mouth  and 
the  cap  malleted  and  burnished  to  the  form  of  the  end  of  the 
root,  so  that  its  edge  will  leave  a  mark  on  the  platinum.  The 
cap,  on  being  removed,  should  be  trimmed  to  this  mark,  and 
again  burnished  on  the  root  (Fig.  139).  Sometimes  around  the 
palatal  portion  of  the  root  the  }:)latinum  may  be  slightly  bur- 
nished over  the  edge.  The  post  is  then  cut  off  just  above  the 
platinum,  and  a  plate  tooth  fitted,  backed,  and  cemented  with 
wax  in  position  on  the  cap.  The  whole  is  then  removed, 
invested,  and  soldered  with  gold  at  least  twenty  carats  fine,  which 
should  be  melted  in  at  the  l)ase  of  the  post,  as  at  this  point, 
when  in  use,  the  strain  is  very  great.  The  post  is  then  barbed, 
and  the  crown  is  cemented  to  the  root  with  gutta-percha  or  oxy- 
phosphate  cement  (Fig.  140). 

Dr.  F.  T.  Van  Woert,  of  Brooklyn,  i^.  Y.,  in  constructing 
crowns  of  this  style,  shapes  the  end  of  the  root,  and  adapts  the 
cap  as  shown  in  Fig.  141.  The  slant  given  to  the  palatal  side 
aids  the  root  to  resist  force  in  a  forward  direction. 


CHAPTER    A'l. 

GOLD   COLLAR   CROWNS. 

This  stvle  of  o-old  crown  iiicludes  tlio.se  iiiethodt^  wliieli  consist 
in  l)anding,  capping,  and  liernietieally  inclosing  with  gold  the 
end  or  the  neck  of  a  root,  with  or  without  any  jiortion  of  a 
natural  crown,  for  the  })urpose  of  securing  stahilitv  to  the  arti- 
ficial crown,  preventing  fracture  of  the  root  and  decay  of  the 
parts,  thus  permanently  preserving  them.  This  method  pos- 
sesses much  practical  vakie  as  a  preserver  of  tooth-structure  and 
restorer  of  usefulness  to  the  teeth,  and  affords  excellent  supports 
for  hridge-work. 

The  use  of  the  collar  crowns  was  first  described  l)y  Dr.  Wm. 
H,  D\\dnelle  in  the  application  of  the  method  to  a  crown  with  a 
porcelain  front,^  and  by  Drs.  W.  N.  Morrison^  and  J.  B.  Beers ^ 
in  the  construction  of  all-gold  cap  crowns. 

Collar  crowns  of  which  the  part  that  essentially  constitutes 
the  cap  is  constructed  in  sections,  will  be  first  described. 

THE    CONSTRUCTION    AND    ADAPTATION    OF    COLLARS. 

Careful  study  of  the  ditterent  forms  of  crowns  and  roots,  and 
of  the  anatomical  structure  and  relationship  of  the  contiguous 
parts,  is  most  essential  for  the  perfect  construction  and  adapta- 
tion of  collars,  ]>ands,  or  ferrules,  as  they  are  variously  designated. 

Many  devices  and  methods  in  use  facilitate  this  operation, 
but  its  skillful  performance  can  oidy  be  attained  by  study  and 
practice,  as  is  proved  by  the  easy  and  perfect  manner  in  which 
it  is  done  by  experts  in  crown-  and  bridge-work,  who  use  no 
a[)pliances  but  pliers  and  shears  guided  by  an  intuitiw  ]»ercei)- 
tion  of  the  requirements  of  each  case. 

^American  Journal  of  Denial  Science,  April,  1855. 
-  Missouri  Dental  Journal,  May,  1869. 
■^Circular  to  dental  profession,  1873. 

79 


80 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


Fig.  142. 


Fig    143. 


The  collar  is  preferably  made  of  coin  gold,  or  of  22  to  23-carat 
gold  plate.  Pure  gold  plate  lined  with  platinum  is  also  used, 
and  iridio-platinum  plate  in  special  cases. 

Gold  plate  of  No.  32  to  No.  34,  or  gold  and  platinum  or 
iridio-platinum  of  No.  34  or  No.  35,  U.  S.  standard  gauge, 
aflbrd  the  requisite  strength,  together  with  easy  adaptation  to 
the  form  of  the  crown  or  root.  The  natural  crown  or  root 
ha\dng  previously  been  properly  pre})ared  (see  page  37),  a  strip 
of  the  metal  is  cut  of  the  length  required,  and  generally  from 
one-fourth  to  one-half  of  an  inch  in  width  (Fig.  142).  The  end 
to  form  the  underlap  is  beyeled  with  a  file.  The  strip  is  then 
bent  with  suital)le  pliers  (Fig.  143)  to  the  average  form  (Fig.  144) 
and  the  size  of  the  cervical  periphery  of 
the  root  of  the  tooth  to  be  crowned,  any 
special  deviation  from  such  average  being 
noted  (Fig.  145).  It  is  then  placed  on  the 
root  and  adapted  as  closely  as  possible  to 
its  form,  with  the  upper  edge  of  the  metal 
pressing  gently  under  the  free  edge  of  any 
portion  of  the  gum  it  may  meet.  It  is  then 
removed  and  cut  so  as  to  allow  the  ends 
to  lap  over  slightly.  The  adaptation  to 
the  root  is  then  continued,  during  which 
process  the  metal  should  be  heated  and 
chilled  in  water  after  each  trial,  in  order 
to  maintain  the  shape  given  to  it.  At  the 
last  adjustment  to  the  root,  the  lap-over  is 
marked  on  the  metal  with  a  sharp-pointed 
instrument.  The  joint  is  made  at  this 
mark  l)y  placing  there  the  least  possible 
quantity  of  solder  and  holding  the  collar  in  the  flame  of  an  alco- 
hol lamp  or  a  blue  gas  flame.  The  collar  is  then  slipped  on  the 
point  of  a  small  anvil,  and  the  joint  tapped  down  and  trimmed 
level. 

When  a  mandrel  is  used  in  forming  a  collar,  the  size  or  shape 
of  the  root  is  first  taken  l^y  encircling  it  with  a  piece  of  fine 
iron  or  copper  wire,  about  No.  28  U.  S.  standard  gauge,  and 
twisting  the  ends  together  on  the  labial  side.     The  Avire  is  then 


THE  CONSTRUCTION  AND  ADAPTATION  OF  COLLARS.        81 

pressed  up  on  tlu'  root  about  as  far  as  the  upper  edge  of  the 

collar  is  to  go,  and  l)uniishc'd  to  the  sides  (Figs.  146  and  147). 

The  wire  ring  is  then  earefnlly  removed,  laid  on  a  piece  of  air- 

chand)er  tin,  a  piece  of  flat  iron  put  over  it,  and  with   a   blow 

from    a    hammer    on    the  Fig.  144. 

iron    the    wire    is    driven 

into   the    tin   (Fig.     148). 

The  wire  ring  is  removed 

from   the  tin,  slipped   on 

a  mandrel  ^  that  represents 

the  form  of  the  root  to  l)e 

crowned  and  pressed  down 

gently  as  far  as  it  will  go 

without  stretching  the  wire 

(A,  Fig.  149).     The  gold 

to  form  the  collar  is  then    ^-.^^^ 

bent    and    shaped    on  the    \      ^^ 

mandrel.    The  edge  which 

is    to    form   the    cervical 

portion    (B)    is  placed    a 

little  below  the  line  of  the 

wire  (A).    The  ends  of  the 

gold  are  l)eveled,  slightly 

lapped,   and   the    edge   of 

the    lap-over    marked    C. 

The  collar  is  then  removed 

from  the  mandrel  and,  the 

ends  being  held  together 

with     common   tweezers, 

which     are     grasped     l)y 

y        ^               1+4-            f'11      1  "  '^'"^  palatal  sido  of  the  superior   molars,  in  many 

pners,    or     Detter     still,    by  cases,  is  of  the  largo  oval  form  indicated  by  the  outer 

a      small      hand-\"ise      (Fig.  I'^e  to  the  formofthe  first  molar.    The  small  spurs  in- 

^     ^,          ,                                     \       &•  dicate  the  points  generally  found  the  most  suitable  to 

15U),     tllC      extreme     outer  make  the  joint. 

end  of  the  Joint  is  united  l)y  an  atom  of  solder  with  a  blow- 
pipe. The  j)oints  of  the  tweezers  prevent  the  solder  from 
flowing  along  the  joint,  leaving  the  cervical  portion  still  open. 

^A  description  of  mandrels  will  be  found  in  the  chapter  on  the  "Mandrel 

System." 

6 


82 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


The  folla]'  is  then  shaped  to  the  form  given  h_v  the  wire  in 
the  tin,  which  haA'ing  l)een  done  it  is  ready  for  adjustment 
in  the  mouth.     The  open  side  permits  the  collar  to  be  easily 


Fig.  145. 


Tig.  146. 


Fig.  147. 


Fig.  148. 


and  accurately  adapted  to  the  root,  after  which  the  solder  can 
be  flowed  across  the  joint. 

When  the  collar  has  been  ff)rmed,  it  is  adjusted  on  the  root 
and  pressed  up  to  the  margin  of  the  gum.  A  line  parallel  with 
the  margin  is  marked  with  a  sharp-pointed  instrument  on  the 
gold  (A,  Figs.   151   and   152).     The    collar   is    then    removed, 


Fig.  149. 


Fig.  150. 


cro 


Fig-  151. 


Fig.   152. 


trimmed  to  this  mark,  readjusted,  ami  again  marked  (B),  and 
the  process  continued  until  the  collar  fits  proportionately  under 
the  mar.u'in  of  the  gum.     The   edge  of  the  collar  is  then  l)nr- 


vmrn  €m3^wm.i!j€mm^3f  Asm  ai»aptat]qs  of  oozz-U^.      x3 


Fi6.  15B. 


'^ 


-=^  ^^ 


:tif  ttSM"  TirntairgTrBi  <<Titf'  iihui-  gnijaaii       fciD'fij 


CHAPTER   VIL 

GOLD   COLLAR  CROWNS  WITH   PORCELAIN   FRONTS. 
INCISORS  AND  CUSPIDS. 

This  style  of  crown  for  incisors  and  cuspids,  as  originally 
made  by  Dr.  C.  M.  Richmond,  and  with  which  his  name  has 
become  associated,  consisted  of  a  cap  for  the  root,  formed  of  a 
band  of  gold  capped  with  platinum  on  which  was  soldered  a 
tooth  with  a  slot  in  the  center  between  the  pins.  Through  this 
slot  a  screw  passed  which  entered  into  a  cylinder  previously 
screwed  and  cemented  into  the  root-canal. 

The  form  of  gold  collar  crown  in  general  use  at  present  is,  in 
principle,  the  same  as  what  has  been  known  in  dentistry  as  a 
gold  pivot  tooth,  with  the  addition  of  a  gold  collar  for  the  root, 
and  having  the  advantage  of  oxyphosphate  for  its  cementation. 
These  improvements,  however,  enhance  its  value  as  a  crown, 
and  materially  change  the  process  of  its  construction.  In 
miaking  an  incisor  or  cuspid  crown  of  this  style,  the  collar, 
having  l)een  formed,  is  trimmed  even  with  the  surface  of  the 
end  of  the  root.  With  the  collar  in  position  on  the  root,  a 
corundum-wheel  is  passed  over  the  labial  edge,  along  the  margin 
of  the  gum,  to  level  the  gold  with  the  root  and  render  it  invisible 
when  the  crown  is  finished.  The  work  will  then  ]:)resent  the 
appearance  shown  in  Fig.  154. 

The  cap  is  made  by  adapting  the  surface  of  a  very  thin  piece 
of  platinum  plate  to  the  Jower  edge  of  the  collar,  and  uniting 
them  with  solder  in  the  flame  of  a  lamp  (Fig.  155).  The  quan- 
tity of  solder  used  must  be  very  small,  and  it  should  be  placed 
on  the  platinum  outside  of  the  collar,  as  otherwise  it  will  flow 
over  the  inside  of  the  collar  and  interfere  with  the  tit  of  the  cap. 
The  platinum  is  then  trimmed  to  the  collar,  and  the  cap  adjusted 
on  the  root.  The  labial  section  of  the  surface  of  the  cap  is 
84 


GOLD  COLLAR  CROWNS   WITH  PORCELAIN  FRONTS. 


85 


tlic'ii  bnrnisliod  to  the  end  of  the  root  (A,  Fig.  154).  Tlie  I'oot- 
canal  liaving  l:)een  sliglitlj  enlarged,  a  pin  of  round  iridio- 
platinum  wdre,  ISTo.  16  or  17,  U.  S.  standard  gaitge, — tiled  a 
little  smaller  for  laterals  or  other  roots  wliieli  require  it, — is 
slightly  tapered  at  the  point,  titted  to  an  aperture  made  in  the 
cap,  and  to  the  canal  (B).  The  pin  is  then  cut  off  even  with  the 
cap,  removed,  and  tem])orarily  laid  aside. 

A  liollow  Avire,  tlic  o]ien  space  in  the  center  of  which  is  very 
small,  has  lately  been  intro(hiced  for  use  in  crown-work  by 
Dr.  J.  G.  Morey.  The  advantage  it  confers  is  the  comparatively 
easv  manner  in  which  it  can   l)e  drilled  out  of  tlie  canal   if  for 


Fig.   154. 


Fig.  155. 


Fig.  156. 


any  reason  it  becomes  necessary  to  remove  the  crown,  as  the 
drill  will  follow  the  tine  opening  in  the  center  of  the  wire. 

A  plain-plate  cross-pin  tooth,  suitable  in  form  and  color,  is 
groinid  and  fitted  in  position  on  the  ca]).  The  lal)io-cervical 
edge  of  the  jiorcelain  (A,  Fig.  156)  should  l)e  flush  with  the  vilga 
of  the  collar,  and  meet  the  margin  of  the  gum.  It  should  be 
cut  out  at  the  base  (B)  so  as  to  form  a  slight  s]>ace  Just  ovei-  the 
end  of  the  ])in.  The  tooth  is  then  l)acke(l  witli  very  thin  ])ure 
gold,  gold  lined  A\ith  platinum,  or  pure  ])latinnm.  Platinum 
gives  a  faint  l»lue  sluule,  and  gold,  or  gold  lined  with  ])latinum, 
if  the  gold  side  is  toward  the  porcelain,  a  slight  yellow  shade. 
The  backing  should  extend  as  far  as  ])<)ssible  under  and  between 
the  tooth  and  the  cap,  as  the  solder  will  flow  in  aiul  fill  the  space, 
thus  giving  strength  and  continuity  of  structure.  The  backing, 
if  bent  over  the  incisive  edge  (C)  at  a  right  angle,  will  ]>rotect 
the  porcelain  in  occlusion.  A  nai-row  strip  of  fine  gold  ]»laced 
transversely  across  at  that  point  ]ire\iousto  investing,  and  united 
in  the  soldering  of  the  backing,  will  answer  the  same  purpose. 


86 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


The  tooth,  Avhen  backed,  is  secured  hi  position  on  the  cap 
with  a  compound  of  wax  and  resin,  and  the  whole  adjusted  in 
the  mouth,  then  removed,  and  the  pin,  which  has  been  laid 
aside,  warmed  and  placed  in  position  by  passing  the  end  from 
the  inside  of  the  cap  through  the  hole  into  the  wax  attaching 
the  porcelain  crown.  Another  adjustment  in  the  mouth  is  then 
made  to  determine  the  exact  line  for  the  pin,  and  the  case  is 
ready  for  investment. 

After  the  fitting  of  the  pin  to  the  root  and  root-canal,  as  has 
been  described  when  the  cap  was  formed,  some  prefer  to  solder 
it  to  the  cap,  for  which  purj^ose  it  should  be  adjusted  in  position 
and  cemented  with  wax,  then  removed,  invested,  and  soldered 
(Fig.  157).  At  this  stage  of  the  work,  if  desired,  an  impression 
can  be  taken  in  a  small  impression  cup  (Fig.  158)  with  either 
plaster  or  modeling  compound.     The  cap  should  l)e  removed  in 


Fig.   158. 


Fig.  159. 


Fig.  160. 


position  in  the  impression.  To  aid  this,  a  piece  of  gutta-percha 
can  be  put  on  the  end  of  the  pin  projecting  from  the  cap.  An 
articulation  of  the  lower  teeth  should  also  be  obtained.  When 
the  model  is  made,  the  pin  is  cut  off  even  with  the  cap,  and  the 
porcelain  tooth  fitted  as  already  described. 

Calcined  marble-dust  and  plaster,  in  the  proportion  of  two 
parts  of  marble-dust  to  one  of  plaster,  to  which  is  added  a  pinch 
of  sulphate  of  potassium  to  quicken  the  setting,  makes  Avhat  is 
considered  to  be  the  most  suitable  investing  material  for  crown- 
work.  The  crown,  when  invested,  should  be  left  exposed  at  the 
sides,  as  illustrated  in  Fig.  159.  The  flame  should  be  pointed 
in  the  direction  A,  and  the  investment  heated  uniformly,  so 
that  the  solder  is  flowed  between  the  jDorcelain  crown  and  the 
cap.     Only  sufiicient  gold  should  be  used  to  insure  restoration 


GOLD  COLLAR  CROWNS   WITH  PORCELAIN  FRONTS. 


87 


of  contour.  When  soldered,  after  having  l)een  placed  in  acid 
and  thoroughly  divested  of  l)()ra\',  the  crown  is  ready  for  the 
finishing  and  polishing  })rocess.  Fig.  160  re[»rescnts  the  com- 
pleted crown. 

BICUSPIDS    AND    MOLARS. 

Bicuspids  crowned  bv  this  method  will  have  greater  strength 
if  a  })ortion  of  the  ])alatal  section  of  tlie  natural  crown  is  reserved 
(Fig.  21),  and  the  hand  or  collar  made  deep  enough  to  cover  it. 

The  end  of  the  root  is  capped  after  the  manner  of  the  fv})ica] 
central  already  described,  one  or  two  ]tins  being  used  in  the 
canals   as   re([nired.     A   porcelain    cusjiid   tooth,    or   a   bicuspid 


Fig.  161. 


Fig.  162. 


Fig.  163. . 


Fig.  165. 


Fig.  166. 


front,  is  then  ground,  l)acked,  and  adjusted  on  the  cap  to  repre- 
sent the  labial  aspect,  and  secured  with  wax.  The  front  and 
cap  are  then  removed,  invested,  and  soldered,  after  which  they 
are  adjusted  in  the  mouth,  and  the  occluding  edge  of  the  por- 
celain is  ground  clear  of  the  antagonizing  teeth  (A,  Fig.  161). 
With  a  die  of  suitable  size  representing  the  occluding  sur- 
face of  a  bicusjiid,  as  illustrated  in  Fig.  162,  a  thin  piece  of  pure 
gold  i>late  is  swaged  (Fig.  163)  and  the  cusps  filled  in  with  18-  or 
20-carat  gold  plate.  The  cap  is  then  trimmed  (Fig.  164).  ground, 
and  fitted  to  the  occluding  edge  of  the  porcelain  front  (Fig.  165) 
in  proper  position  as  regards  occlusion,  and  the  wax  attaching 
it  is  shaped  to  the  contour  of  the  crown  (A).  A  piece  of  pure 
gold  plate  (B),  not  over  34  or  35  U.  S.  standard  gauge,  is  then 
adjusted  on  each  side  of  the  crown,  which  is  invested  (Fig.  166). 
The  long  ends  of  the  t\vo  side-]tieces  of  gold  plate  are  desio-nod 
to  retain  them  in  position,  as  the  investing  material  should  be 
removed  from  tlu'  portion  inclosing  the  sides  of  the  crown  (A). 
In  the  jirocess  of  soldering  the  solder  is  placi.'d  in  the  aperture 


88  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

at  B,  and  tlie  flame  of  the  blow-pix)e  V)eing  directed  on  the  ex- 
posed sides  of  the  gokl  at  A,  the  sokler  is  flowed  into  every 
part,  forming  perfect  continuity  of  structure  of  the  metallic  por- 
tion of  the  crown.  In  finishing,  the  surplus  gold  is  trimmed  to 
the  contour  of  a  bicuspid  tooth.  Fig.  167  represents  the  finished 
crown. 

The  method  descril)ed  produces  a  perfect  and  artistically 
formed  crown,  but  simpler  and  quicker  methods  are  practiced. 
One  of  these  is  to  build  up  the  palatal  cusp  with  several  pieces 
of  gokl  plate,  which  have  been  previously  melted  into  the  form 
of  small  balls  and  flattened  out  on  an  anvil.  These,  laid  in  posi- 
tion and  united  with  solder,  are  shaped  in  finishing  to  represent 


Fig.  167. 


Fig.  168. 


Fig.  170. 


the  palatal  cusp  (Fig.  168).  Tlie  porcelain  front  should  be 
backed  so  that  the  solder  can  be  flowed  over  its  occluding  edge. 

Another  method  is  to  extend  the  palatal  part  of  the  collar  down 
as  shown  in  Fig.  169,  and  then  fill  in  the  space  with  solder. 
In  finishing,  the  gold  is  trimmed  to  the  form  of  the  croA\'n. 

The  method  of  construction  of  molar  crowns  ^vith  porcelain 
fronts  is  similar  to  that  for  bicuspids  (Fig.  170). 

Dr.  StoiceU's  Jlethotf. — A  porcelain  crown  can  be  soldered 
on  the  cap,  according  to  Dr.  S.  S.  Stowell's  method,  as  follows  :  ^ 
"  The  tooth  used  may  be  a  Logan  or  an  E.  Parmly  Brown  crown 
or  an  ordinary  countersunk  tooth,  but  in  most  cases  the  Logan 
crown  is  preferable.  The  pin  is  first  cut  ofi",  then  the  tooth  is 
ground  to  fit  on  the  cap ;  porcelain  and  the  stump  of  the  pin 
being  reduced  alike  evenly  and  smoothly,  after  which  the  stumji 
of  the  pin  is  ground  with  a  small  wheel  below  the  surface  of 
the  porcelain  (Fig.  171).     The  tooth  is  then  invested  (Fig.  172) 


'  Dental  Cosjnos,  vol.  xxix,  page  641. 


ALL-GOLD  COLLAR  CROWNS  COXSTRUCTED  IN  SECTIONS.     89 


and  pure  gold  fused  on  to  the  platinum  pin,  and  while  in  a  fluid 
state  it  is  with  a  wax  spatula  "spatted"  down  flat  (Fig.  173). 
The  gold  is  then  tiled  or  ground  down  even  with  the  porcelain, 


Fig.  171. 


Fig.  172. 


Fig.  173. 


Fig.  174. 


Fig.  175. 


and  at  the  palatal  border  the  tooth  is  ground  to  bevel  back  until 
the  gold  is  reached  (Fig.  174).  The  tooth  is  then  secured  in 
place  on  the  cap  with  wax  cement  (Fig.  175),  the  case  invested, 
and  heated  until  the  wax  has  melted  and  burned  out.  A  small 
clipping  of  thin  platinum  plate  is  crowded  into  the  opening  (Fig. 
176)  caused  bv  the  grinding  of  the  bevel  on  the  crown.  The 
clipping  of  platinum  serves  as  a  lead  for  the  solder,  which  fol- 
lows it  down  into  the  countersunk  cap,  around  the  ends  of  the 
dowels,  and  Anally  attaches  itself  to  the  pure  gold  already  at- 
tached to  the  stum})  of  the  platinum  pin.  Fig.  177  rejtresents 
the  completed  crown.     A  sectional   view  of  a  like  crown  (Fig. 

Fig.  176.  Fig.  177.  Fig.  178.  Fig.  179.  Fig.  180. 


178)  also  shows  the  organi/.ation  in  detail.  A  porcelain  crown 
can  be  used  to  re])resent  any  of  the  teeth  in  the  same  manner. 
See  Figs.  179  and  180." 

ALL-GOLD    COLLAR    CROWNS     FOR    BICU3PID3    AND    MOLARS 
CONSTRUCTED     IN     SECTIONS. 

The  root  and  ci'owii  liavingl)een  ]»roperly  pi'epared.  tlie  eollai' 
is  formed  and  adjusted  as  described  at  juige  80,  and  the  edge 
toAvard  the  antau'oniziuii-  teeth  trimmed,  to  fullv  clear  them  in 


90 


ARTIFICIAL  CROWX-  AXD  BRIDGE-WORK. 


Fig.  181. 


oecliisioii.     The    collar  is    then  slightly  expanded  toward  the 
oreluding  snrfaee  to  eifect  contour,  removed,  filled  with  plaster, 

and  adjusted  in  position.  Fig.  181  rep- 
resents a  typical  case.  The  antagonizing 
teeth,  having  heen  covered  with  a  piece 
of  tin  foil,  are  then  occluded  until  the 
plaster  sets.  The  collar  is  then  removed. 
The  surface  of  the  plaster  inside  the 
collar  will  give  the  impression  of  the 
natural  root  or  crown,  and  the  outside 
that  of  the  antagonizing  teeth.  The  latter  furnishes  an  outline 
of  the  grinding-surface  of  the  crown. 

The  plaster  is  then  trimmed  and  shaped  to  represent  the  cusps 
and  fissures  of  the  natural  tooth,  enough  of  the  surface  l)eing 
removed  to  allow  fov  the  thickness  of  the  plate  that  forms  the 
cap.  Eeadjustment  in  the  mouth  will  show  the  accuracy  of 
the  occlusion. 

A  small  tube  of  copper,  a  trifle  larger  in  circumference  tlu\n 
the  crown  under  construction,  is  filled  with  Melotte's  "  Moldine," 
and  the  surface  rubbed  with  soapstone.     An  impression  of  the 

lower  portion  of  the  form  of  the 
crown  A  to  the  line  B,  Fig.  182, 
is  then  made  in  the  moldine, 
and  a  strip  (^f  paper  wound 
around  the  tube,  extending 
about  an  inch  above  the  edge. 
Fusible  alloy  is  then  melted  and 
})Oured  into  the  mold,  thus 
forming  a  die.  An  indentation 
is  made  with  a  |)unch  in  a 
block  of  lead,  into  which  the 
die,  when  cold,  is  hammered 
slightly  beyond  the  inqiression 
of  the  edge  of  the  collar.  By  this  method  a  die  and  a  counter- 
die  (Fig.  183)  can,  with  practice,  be  completed  in  five  minutes. 
Witli  this  die  the  cap  is  then  struck  up  on  the  lead  from  a  flat 
piece  of  plate  and  fitted  to  the  collar.  A  little  of  the  surface 
(jf  the  plaster  in  the  collar  may  have  to  be  removed,  if,  on  trial 


Fig.  182. 


Fig.  183. 


A,  Fusible  die. 

B,  Counter-die. 

C,  Plate  to  form  the 
c-up. 


ALL-GOLD  COLLAR  CliOWSS  CONSTRUCTED  IX  SECT/OXS-    91 

ill  tlir  mouth,  rlie  r-A\>  is  t'oiiiid  a  littlr  'Husli.  Tlic  crown,  with 
the  }>laster  still  inside  the  collar,  is  then  lixed  in  a  solderinii" 
clamp  constructed  as  sliown  in  Figs.  184  or  185,  which  holds 
tlie  parts  toiivther  and  permits  tlie  flame  to  reach  all  jioints. 
Xo  more  solder  should  l)e  used  to  unite  the  edges  than  the  con- 
tour re(piires,  as  an  excess  necessitates  additional  lahor  in  fin- 
ishing. 

Another  method  is,  when  the  cap  is  stiT.ck  up,  to  melt  solder 
into  the  cusps,  and  then  adjust  tlie  ca]»  in  position  on  the  collar, 
tor  which  purpose  some  of  tlie  plaster  underneath  the  cap  must 
l)e  removed.  A  jet  of  flame  from  the  lilow-pipe  is  then  thrown 
upon  it  in  such  a  wav  as  to  cause  the  solder  to  flow  (hnvn  on  the 


Fig.  184. 


Fig.  18.",. 


The  frame  of  thi?  clamp  is  formed  of  iron  wire,  and  the 
supi)ort  for  the  crown  of  phxster,  asbe.?tos,  and  marble-dust. 


edge  of  the  collar  and  fill  the  seam  on  the  inside.  The  ohjeetion 
to  this  method  is  that,  when  a  large  jtortion  of  the  natural  crown 
is  inclosed  hv  the  gold,  the  solder  will  occasionally  alter  the  inside 
form  of  the  fitted  cap,  causing  a  defect  trouhlesome  to  correct. 

Still  another  method  is  to  adjust  the  collar  in  the  moutli,  and, 
with  a  small  piece  of  wax  or  impression-compound  pressed 
upon  it,  to  take  an  impression  and  "  hite,"  in  which  the  collar 
wnll  he  inil»edded  and  removed.  With  this  a  model  and  articu- 
lation are  made  and  the  form  of  the  c-ap  shaped  in  wax.  An 
impression  of  the  ca]i  is  then  made,  either  in  nioldiiie  in  a  soft 
state  in  a  tuhe,  or  in  plaster,  and  a  die  cast.  The  cap  is  stamited 
on  this  die,  then  adapted  to  the  collar  hv  the  model,  and  the 
crown  finished.  This  method,  which  was  first  made  known  hv 
Dr.  N.  W.  Kingslev,  is  ado}»ted  when  it  is  preferahle  to  construct 
the  crown  l)etween  the  visits  of  the  ])atient. 


92 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


The  methods  deserihed  insure  a  perfect  occhision  of  the 
crown  ^^ith  the  antagonizing  teeth.  In  the  absence  of  antagon- 
izing teeth,  or  when  the  general  form  of  the  grinding  surface 
permits  it,  the  cap  can  be  struck  up  with  a  die  formed  similar  to 
the  one  shown  in  Fig.  186,  corresponding  to  the  surface  of  the 
tooth  crowned,  by  laving  a  piece  of  plate  on  a  block  of  lead  and 
liammering  tlic  die  into  it.  The  cusps  are  then  tilled  in,  and 
the  edges  of  the  inner  surface  of  the  cap  ground  level  on  the 
side  of  a  corundum-wheel.  The  entire  circumference  of  the 
edge   of  the   collar  is  also  leveled,  and  the  cap  adjusted  and 


Fig.  186. 


Fig.  187. 
/  / 


Fig.  188. 


'^laui'- 


soldered  as  already  described.  If  the  cusps  of  the  cap  were 
filled  in  with  solder,  it  will  flow  down  and  join  the  collar  on  the 
inside ;  if  with  gold  plate,  the  cap  and  collar  must  be  joined 
with  solder  on  the  outside. 

Another  method  of  connecting  a  solid  gold  cap  to  a  collar  is 
to  cut  the  lower  edge  of  the  collar  in  several  places  (Fig.  187) 
and  bend  it  inward,  over  tlie  crown  or  root.  Then  adjust  and 
clani])  the  solid  gold  erown  cap  in  pro])er  position  on  the  collar, 
and  till  the  ga})  (A,  Fig.  188)  around  the  edge  of  the  cap  with 
solder. 

Metallic  caps,  or  forms  of  the  occluding  surfaces  of  teeth  for 
use  in  constructing  crowns,  are  quickly  made  with  the  die-plate 
shown  in  Fig.  189,^  "  in  winch  are  four  groups  of  intaglio  dies 
^  Dental  Cosmos,  vol.  xxix,  page  482. 


ALL-GOLD  COLLAR  CROWNS  CONSTRUCTED  IN  SECTIONS.    93 


representing,  with  distinctive  correctness,  the  pecnliar  cusps  of  the 
upper  and  lower  riglit  and  left  bicuspids  and  molars.  These  are 
indicated  by  the  Hillischer  notation,  so  that  each  form  may  be 


easily  identilied  in  practice.  The  hul)s  A,  13  (Fig.  190)  are  of  the 
sizes  shown,  and  are  made  of  an  alloy  composedjof  tin  one  part, 
lead  four  i>arrs,  melted  togctht'r.  The  mold  C'  should  be  warmed, 
the  metal  alloy  poured  in  every  hole,  and  the  ovi-rilow  wiped  off 
just  before  the  metal  stitfens :   this  will   make  the  butts  of  the 


94 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


liubs  sniootli  and  flat.  After  a  minute  or  two  the  mold  may 
be  rever^^ed,  the  hul)s  shaken  out,  and  the  easting  [)rocess  eon- 
tinued  until  a  considerable  number  of  hubs  shall  have  been 
made.     In  Fig.  191,  a  molar  hub  is  shown  in  place  on  a  piece 


Fig.  190. 


(jf  No.  32  gold  plate,  which  lies  over  the  6*  (upper  right  first 
molar)  die.  A  succession  of  l)lows  on  the  hul)  with  a  four- 
pound  smooth-face  hammer  Avill  drive  the  plate  into  the  die,  and, 
at  the  same  time,  s[)read  the  hub  metal  from  the  die  center  to  its 

circumference,  in  such  a  man- 
^'^^-  1^'-  ner    that    the    plate    will    ])e 

})erfectly  struck  up  with  the 
least  possible  risk  of  being 
cracked.  Tlie  iiattened  hub 
is  seen  in  Fig.  192,  which  also 
shows  at  D  the  ob^'erse  of  the 
struck-u])  hub,  and  at  E  the 
cameo  of  the  struck-up  plate, 
having  every  cUvSp  and  de- 
pression of  6"  sharply  defined. 
The  counter-die  ])late  (Fig. 
180)  is  made  of  a  very  hard  cast  metal,  M'hich  will  admit  of 
the  striking  up  of  many  crown  plates  by  the  means  descril)ed, 
if  tlie  crown  plates  be  not  too  thick  and  stiff.  Of  course  they 
should   be  aniu'aled  before  they  are  placed  o\'er  the  die. 


ALL-GOLD    COLLAR  CROWNS  CONSTRUCTED  IN  SECTIONS.    95 


"In  careful  hands  the  die-])! ate  should  give  clear  cusp  defini- 
tions after  years  of  use-.  The  counter-die  plate  is  in  some  re- 
spects similar  to  a  stereotype  ])late  for  printing,  and  the  struck 
impressions  on  twt)  strips  of  thin  plate  will  therefore  a]>[>ear  as 
in  Fig.  193,  wherein  their  regular  order  is  noticeable,  as  seen 
from  the  cameo  surface  of  the  struck  plates. 

"  The  peculiar  action  of  tlie  huh  in  forming  first  the  center  of 
the  crown  plate,  and  spreading  from  the  center  outwards,  as  the 
hub  is  shortened  under  the  hammer,  until  the  die  is  overspread 
by  the  plate  and  huh,  with  the  result  shown  in  Fig.  192,  is  an 
essential  feature  of  this  process  for  obtaining  easily  and  (piickly 
the  superior  styles  of  coronal    cameos  shown.      If  a   cusp  or 


Fig.  192. 


aieHY 


fissure  should  chance  t(t  crack  in  huhbiug,  a  small  piece  of 
]>late  may  l)e  struck  up  o\er  the  fissure,  and  then  soldered  to  the 
original  cap." 

Fig.  194  represents  a  case  of  abrasion  of  tlic  lower  teeth,  to 
which  all-gold  crowns  have  been  applied,  as  shown  in  Fig,  195. 
In  such  cases,  owing  to  the  aggression  of  the  occluding  teeth, 
the  cap  forming  the  occluding  surface  should  be  constructed  of 
gold  and  ])latinuni  plate.  An  artificial  plate  replaces  the  upper 
teeth. 

The  roots  of  a  molar  decayed  apart  at  the  bifurcation  can 
often  be  crowned  ser\'iceably  by  making  a  cap  for  each  I'oot 
separately,  ami  then  soldering  the  sides  of  the  ca]i  togt'ther  (Fig. 
196).  Where  one  root  is  missing,  the  other  can  be  crowned 
siuii'lv. 


96 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


Figs.  197  and  198  represent  Dr.  J.  N.  Farrar's  cantilever- 
crowns.  He  describes  them  as  follows :  Fig.  197  illustrates  a 
sectional  view  of  three  teeth,  and  an  amputated  first  bicuspid 


r"^' 


L^  I 


P=H  f"* 


It:- 


I'r 


h4 


I-*   J 


^'1 


E-i 


\^\ 


root  preserved  by  a  screw,  sho^\ang  the  application  of  the  canti- 
lever crown  T,  P,  set  upon  the  decayed  second  bicuspid  and 
made  to  project  over  to  bridge  the  space^formed  by  the  loss  of 
the  first  bicuspid,  and  resting  in  eontact  with  the  cuspid  so  as  to 


ALL-GOLD  COLLAR  CROU'XS  CONSTRUCTED  IN  SECTIONS.    97 

connect  the  broken  line  of  niastieatin<i'  snrtaees  and  prevent 
tilting  forward  of  the  second  l)icnspi(l.  Fig.  19S  ilhistrates  the 
appearance  of  two  molars,  the  posterior  half  of  one  of  which  is 

Fig.  194. 


destroyed,  showing  also  the  ajiplication  of  two  thimble-crowns, 
which  are  constrncted  so  as  to  form  a  cantilever  bridge  over  the 
chasm  by  locking  midway  in  such  a  maimer  as  to  prevent  tilting 


Fig.  195. 


ov  sliding  of  surfaces.  an<l  at  the  same  time  be  easily  cleansed 
by  a  (piill  or  thread.  The  abscessed  root  here  shown  was  ex- 
tracted.^ 

^  Dental  Cosmos,  vol.  xxvi,  No.  3. 


98 


ARTIFICIAL  CROWN-  AND  BRIDGE- WOMK. 


COLLAR    CROWNS     HYGIENICALLY    CONSIDERED. 

The  principal  arii'unieiit  against  ferruled  or  collared  crowns  is 
that  they  are  productive  of  irritation  to  the  peridental  mem- 
brane, ultimately  causing  its  absorption  and  the  exposure  of  the 
collar.  This  would  l)e  theoreticallv  and  practically  true  of  a 
rough  or  porous  substan'ce  encircling  the  root,  or  of  an  imper- 
fectly aild  unskillfully  adjusted  ferrule 
or  collar  which  would  by  its  presence 
hold  a  position  analogous  to  a  calcareous 
deposit,  but  no  such  comparison  can  be 
made  in  regard  to  a  perfectly  fitted 
collar,  forming  at  its  edge  a  smooth 
and  imperceptible  union  with  the  sides 
of  the  root,  and  presenting  a  uniform 

In    case  of 

perfectly  adapted  collars,  when  any  irritation  of  the  membrane 
exists,  it  will  be  found  to  result  from  such  causes  as  usually 
produce  it  when  the  natural  crowns  are  present,  namely,  den- 
tal concretions.  A  tarnished  and  unclean  condition  of  the 
surface  of  the  gold  of  the  collar  will  produce  an  irritation  of 

Pig.  197.  Pig.  198. 


and   benign  surface  to  the  investing  membrane. 


the  meml)ranes,  whicli  is  a  matter  inde}>endent  of  the  collar  itself, 
and  easily  remedied  by  cleansing  and  polishing  the  surface. 
"Where  an  acid  condition  of  the  secretions  of  the  mouth  exists, 
a  collar  of  jilatinum  and  iridium,  or  one  of  gold  and  platinum 
crown-metal,  presenting  the  platinum  surface,  is  suggested  in 
prefei'ence  to  gold,  as  these  metals  will  not  be  afi:ected,  but  will 
constantly  present  an  untarinslied  surface. 


CHAPTER  YIII. 


THE    GOLD    SEAMLESS    CAP    CROWISr. 


This  iiietliod  consists  in  tlic  use  of  a  i>'ol(l  seamless  cap  for  the 
eonstrnction  of  tlie  re([uii'e(l  root  cap  or  crown. 

INC1SOR3,    CUSPIDS,    AND    BICUSPIDS. 

Incisor,  cusjiid,  and  l)icuspid  erowns  with  porcelain  fronts  are 
constructed  hy  tins  method  as  follows:  The  natural  crown  !;< 
li'round  down  to  witliin  ahout  one-eiii'lith  of  an  inch  of  the  gwm 
at  the  })alatal  wall,  or  enouiJ-h  to  clear  the  anta^'onizing  teeth 
when  occluded,  and  slanting'  from  the  posterior  edge  of  the 
])ulp-chaml)er  to  the  cervico-lahial  edge  of  the  gum  and  slightly 
under  its  margin  if  it  is  desirable  to  conceal  the  Joining  of  the 
crown  with  the  root.  The  sides  are  shaped  the  same  as  for  a 
collar  crown  (Fig.  199).  A  die  of  the  end  of  tlie  root  is  then 
made.  For  this  purpose  an  impression  of  the  part  is  taken  with 
gutta-}»ercha  on  the  end  of  a  piece  of  wood 
trimmed  to  the  pro])er  size,  or  by  placing 
the  gutta-^ierclia  in  a  tube  formed  of  a  strip 
of  copper  about  one  and  one-half  inches  in 
length  and  tlu'ce-eighths  of  an  inch  in  di- 
ameter, cut  out  on  the  sides  to  the  depth  of 
half  an  inch,  with  the  flange  for  the  ])alatal 
side  shortened  (Fig.  200).  The  impivssion 
thus  taken  will  be  coniined  almost  entirely 
to  the  end  of  the  root  to  be  capped.      When 

the  gutta-percha  has  cooled,  a  stri[»  of  paper  is  tied  around  the 
wood  or  tube  and  a  die  cast  with  the  fusibh-  metal.  "When  cool, 
the  die  is  remo\ed  from  tlie  molib  and  tlu'  metal  is  trimmed, 
with  tik-  and  i-hisel,  a  little  (k'cper  than  the  gum  has  permitted 
tlie  impression  of  the  root  t(-»  be  tak(.'n,  and  without  altering  the 

99 


Fig.   199. 


Fig.  200. 


100 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


form  of  the  end  of  tlie  root  (Fig.  201).  A  counter-die  is  then 
made  hv  punching  a  hole  in  a  level  mass  of  pure  lead,  and  with 
a  few  hlows  of  a  hammer  driving  the  die  into  it. 

A  cap  of  gold  can  be  formed  by  placing  a  piece  of  gold  plate 
(preferably  pure,  ITo.  32  U.  S.  standard  gauge)  of  suitable  size  upon 
a  block  of  lead,  and  with  an  oval-shaped  punch  one-fourth  of  an 
inch  in  diameter  gradually  driving  it  into  the  lead  until  the  gold 
has  assumed  the  shape  of  a  cap  about  a  quarter-inch  in  depth  (A, 
Fig.  201).  The  gold  should  be  withdrawn  from  under  the  punch 
and  annealed  several  times  during  the  process.  Caps  can  also  be 
m.ade  with  a  stamping  press  such  as  was  introduced  by  Dr.  J.  J. 
R.  Patrick.     (See  page  107.) 


Fig.  201 


Fig.  202. 


Fig.  204. 


Fig.  203. 


•  The  ca]»  is  then  annealed  and  swaged  on  the  die  to  the  form 
of  ihQ  end  of  the  root  (B,  Fig.  201).  The  palatal  portion  of  the  cap 
should  be  allowed  to  go  well  up  under  the  free  edge  of  the  gum, 
and  at  the  cervico-lal)ial  edge  it  can  be,  if  preferred,  cut  out  to 
the  edge  of  the  root.  In  the  process  of  adjustment,  the  edges 
that  fit  under  the  gum  should  be  marked  and  trimmed  as 
directed  in  describing  the  construction  of  a  collar  crown,  and 
then  burnished  close  to  the  sides  of  the  root  and  into  the  orifice 
of  the  root-canal,  forming  a  perfect-fitting  seamless  cap  (Fig. 
202).  An  iridio-platinum  ])in  is  then  fitted  in  the  root-canal  and 
sol<lci-cd   to  the  cap  (Fig.  203),  or  aftervvai'd   adjusted  as  in  the 


THE  GOLD  SEAMLESS  CAP  CROWN.  101 

construction  of  the  gold  collar  crown  with  porcelain  front  (page 
85),  with  which  operation  the  remainder  of  the  process  of 
construction  is  identical.  Fig.  204  represents  the  completed 
crown. 

The  advantages  of  this  style  of  crown  are,  simplicity,  as  tlie  for- 
mation of  a  collar  is  avoided,  and  strength,  as  a  large  portion  of 
the  natural  crown  can  l)e  left  at  the  ])alatal  side.  This  affords  a 
stronger  and  more  reliable  foundation  than  can  be  ohtained  at 
any  other  point,  as  the  direction  of  the  force  in  mastication  is 
forward  at  an  angle  ^\•ith  tlie  line  of  tlie  root,  and  although  the 
gold  of  the  cap,  where  it  encircles  the  root  at  the  cervi co-labial 
edge,  is  entirely  removed,  the  crown  is  still  held  securely. 

In  a  paper  on  the  sulijeet  of  preserving  and  utilizing  this  part 
of  the  tooth,  Dr.  W.  F.  Litch,  of  Philadelphia,  descrihes  a 
crowning  operation.^  He  constructed  the  cap  of  platinum  by 
slitting  a  piece  of  the  plate  in  a  number  of  places,  adapting  it  to 
the  form  of  the  end  of  the  root,  and  then  soldering  the  whole 
together. 

This  operaticm  was  not,  however,  so  easily  or  so  satisfactorily 
performed  as  the  method  above  described,  in  which  platinum,  if 
desired,  can  be  used  instead  of  gold,  and  the  soldering  done  with 
22-  or  24-carat  gold.  In  some  respects  pure  platinum  is  pi*efer- 
able  to  gold  in  capping  roots,  as  it  is  less  likely  to  be  affected  by 
the  secretions  of  the  mouth. 

BICUSPIDS   AND   MOLARS. 

All-gold  seamless  crowns  for  bicuspids  and  molars  that  will 
accurately  fit  the  natural  crown  and  root,  and  occlude  projterly 
with  the  antagonizing  teeth,  are  easily  and  ([uickl}''  formed,  it 
sutficient  of  tlie  natural  crown  remains  to  advnit  of  tempc^^ary 
i-estoration  of  its  contour  with  gutta-])erclia  or  any  other  suit- 
able plastic  material.  Wlieu  this  has  l)een  done,  an  imjtression 
of  the  restored  tooth  is  taken  in  gutta-jiercha  in  a  tube,  as  ex- 
plained on  page  99,  and  a  die  then  formed  of  fusible  alloy;  or 
a  plaster  model  can  be  made  from  ;ni  im[iression  of  the  tooth 
taken  in  wax,  and  a  mold  obtained  from  the  model. 

The  [)reparati()n  and    shaping  of   the   natural   crown,  to  re- 


'  Dented  Cosmos,  vol.  xxv,  No.  9,  page  449. 


102  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

ceive  the  artificial  crown,  can  then  be  proceeded  with.  Where 
the  natural  crown  is  very  badly  decayed  or  broken  down  and 
the  method  just  described,  is  not  practicable,  the  portion  of 
the  natural  crown  or  root  remaining  should  be  shaped  and  pre- 
pared to  receive  an  artificial  crown.  Then  the  form  of  the 
cer^Hx  is  ascertained  with  a  wire  as  described  on  page  81,  and 
an  impression  of  the  parts  taken  in  wax,  and  the  Avire  form,  the 
twisted  ends  having  been  shortened,  is  carefully  adjusted  on  the 
wax  at  the  cervical  line.  The  plaster  model,  when  made,  will 
show^  the  wire  slightly  imbedded  in  the  plaster.  The  plaster 
should  be  trimmed  to  the  inner  edge  of  the  wire,  as  that  repre- 
sents the  exact  form  of  the  root  (Fig.  205.) 

Another  method  is  to  encircle  and  adapt  to  the  form  of  the 
root  a  strip  of  annealed  copper,  ISTo.  35  standard  gauge,  al)()ut 

Fig.  205.  "Fig.  206. 


one-eighth  of  an  inch  wide.  The  co})per  is  then  removed,  the 
ends  heated  and  touched  with  resin  and  wax,  the  copper  adjusted 
on  the  root,  and  the  ends  cemented  with  a  warm  instrument. 
An  impression  is  next  taken  A\'ith  plaster,  in  which  the  copper 
band  is  removed  in  position.  A  model  made  from  this  iinpres- 
jsioii,  after  the^copper  is  removed,  presents  the  exact  form  of  the 
root. 

From  a  "  bite  "  taken  in  wax  a  plaster  articulation  is  then  made  . 
to  the  model.  A  hole  is  then  drilled  in  the  center  of  the  form 
of  the  root  on  the  model  to  be  crowned.  In  this  hole,  and  over 
the  end  of  the  root,  a  ball  of  soft  plaster,  slightly  colored  with 
carmine,  is  placed,  and  the  teeth  of  the  articulation  covered 
with  tin-foil  closed  on  it.  This,  on  separation,  gives  the  outline 
of  the  fonii  of  the  ii-rindi no-surface  for  the  crown.     The  sides  of 


THE  GOLD  SEAMLESS  CAP  CROWX. 


103 


the  plaster  are  then  trimmed  to  the  form  of  the  crown,  and  the 
whole  carved  in  detail  (Fig.  206).  A.-^  the  crown  will  always 
stamp  larger  in  circumference  than  the  die,  in  proportion  to 
the  thickness  of  the  gold  used,  an  allowance  must  be  made 
by  trimming  off  a  pro}»ortionate  amount  of  the  surface  of 
the  model;  otherwise  the  outer  surface  of  the  crown  will  he 
larger  than  is  desired.  "\Ylien  tlie  ])laster  model  for  the  erown 
is  made,  it  is  se])arated  from  the  rest  of  the  model  at  the  dotted 
line  seen  in  Fig.  206  and  trimmed  in  the  form  shown  by  the  east 
A,  Fig.  207.  From  this  model  the  die  is  made  in  a  tul)e  witli 
moldine  and  fusil)le  metal  as  described  *at  page  99.  The  cast 
should  always  be  lengthened  at  the  neck,  so  that  the  crown 
when  constructed  shall  have  a  surplus  in  depth  of  gold  to  allow 
for  any  trimming  or  shaping  of  the  collar  that  may  be  required. 
The   counter-die  (B,  Fig.  207)  is  made  by  punching  a  hole  in 


Fig.  207. 


Fio.  208. 


Fig.  209. 


a  bloek  of  lead  and  hammering  the  die  into  it. 
^  The  crown,  wliich  is  usualh'  formed  of  pure  gold, 

or  gold  slightly  alloyed,  or  gold  lined  with  very 
thin  platinum  from  Xo.  32  to  Xo.  34,  U.  S.  standard  gauge,  is 
then  made  by  first  stamping  a  piece  of  plate  (see  page  105)  in 
the  form  of  a  cap  of  gold  (A,  Fig.  20S).  This  cap  is  then  i»laced 
on  the  cast  and  with  the  aid  of  the  eounter-die  (B,  Fig.  207) 
swaged  to  the  form  of  the  crown  B,  Fig.  20S.  A  piece  of  kid 
leather  should  be  used  to  cover  and  protect  the  gold  from  the 
lead,  and  facilitate  its  removal  from  the  counter-die.  An  allow- 
ance for  the  thickness  of  the  leather  must  be  first  made,  by 
driving  it  on  the  cast  without  the  gold,  into  the  counter-die  to 
enlarge  it.  If  this  is  not  done,  the  gold  is  liable  to  be  torn  in 
the  swaging. 

Cuspid  crowns  from  which  a  portion  of  the  gold  on  the  lalnal 


104  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

aspect  is  to  be  removed,  or  which  are  to  he  used  entire  as  a 
support  for  bridge-work,  can  usually  be  advantageously  formed 
with  a  seamless  cap  (Fig.  209).  The  necks  of  these  crowns  can 
be  contracted  in  fitting  in  a  contracting  plate,  or  slit,  lapped,  and 
soldered,  should  the  case  so  require.  (For  details  of  process  of 
adjustment  and  insertion,  see  "Process  of  Adjustment  of  Seam- 
less Contour  Crowns.") 


CHAPTER   IX. 

GOLD    SEAMLESS    CONTOUR    CROWNS. 

The  artistic  requirement  of  all-gold  crown-work  is,  that  it 
shall  reproduce  the  anatomical  contour  of  the  natural  teeth. 
This  is  usually  accomplished  by  melting  solder  on  the  collar  and 
then  trimming  it  to  the  form  of  the  crown.  A  preferable 
method  is  to  shape  the  metal  forming  the  sides  of  the  crown  by 
swaging.  This  is  easih'  done  in  a  crown  formed  in  sections,  but  a 
special  process  is  re([uired  in  the  construction  of  seamless  crowns. 

A  contour  crown  can  be  made  by  placing  a  seamless  cap  on  a 
sectional  die  or  mandrel  of  the  shape  of  tlie  tooth,  first  swaging 


Fig.  210. 


Fig.  2n. 


Fig.  -212. 


r 

1  ^  : 

^ 

g; 

J, 

^' 

-_  - ■    -^ 

|t 

1 

1 

_u 

thegrinding-surfaee  on  the  mandrel  and  then  stamping  downward 
on  the  straight  sides  of  the  crown  with  a  cap  iitted  to  the  shank 
part  of  the  mandrel.  But  such  a  process,  like  many  others,  is  too 
complicated  to  be  of  any  use  to  the  dental  practitioner.  Tlie 
sectional  mold  method  here  presented  is  simple,  practical,  and 
general  in  its  application. 

To  describe  and  illustrate  the  process,  we  will  take  one  of 
the  most  difficult  crowns  to  construct, — a  superior  molar  (Fig. 
210).  A  natural  tooth,  or  one  made  of  plaster,  is  used  as  a 
model.  From  this  a  sectional  mold  is  made,  as  illustrated  in 
Figs.  211  and   212,  in   Babbitt's  metal,  zinc,  or  fusible  alloy. 

105 


106 


ARTIFICIAL  CROWN-  AND  BRIDQE-WORK. 


Into  the  mold  a  cap  of  gold  (Fig.  213)  23  to  24  carats  fine  is 
adjusted,  fitting  tightly  the  orifice  of  the  closed  mold.  The 
mold  is  then  placed  in  a  vise,  and  the  cap  is  expanded  to  the 
general  form  of  the  mold  by  hammering  into  it  a  mass  of  cotton. 
The  gold  is  then  swaged  more  in  detail  to  the  form,  and  with  a 
wood  point  or  a  burnisher  revolved  by  the  dental  engine  bur- 
nished after  the  method  of  Dr.  Herbst  into  every  part  of  the 
mold  (Fig.  214).  To  facilitate  the  process,  the  mold  should  be 
frequently  opened,  and  the  gold  annealed.  Fig.  215  represents  the 
completed  crown.  These  results  can  l)e  secured  l:)y  other  styles 
of  molds  :  Fig.  214  illustrates  one,  but  the  principle  is  the  same. 
Another  method  is  to  form  a  fusible-metal  die  of  the  tooth  to 


Fig.  214. 


Fig.  215. 


be  crowned,  and,  after  having  stamped  the  grinding-surface  of 
the  crown,  to  reverse  and  swage  the  sides  close  to  the  die;  the 
crown  is  then  relieved  of  the  core  (die)  by  heating  to  the  melting- 
point  of  the  fusible  metal  and  pouring  it  out. 

For  practical  use,  a  variety  of  molds  should  be  made  from 
natural  teeth  of  different  sizes  and  average  forms  to  serve  in 
corresponding  cases.  The  crowns  should  be  contracted  at  the 
neck  more  than  their  size  and  contour  call  for,  so  that  the  gold 
will  act  as  a  tight-fitting  band  which  will  expand  to  the  form  of 
the  root  as  the  crown  is  pressed  up  in  the  process  of  adjustment. 

Caps  of  metal  can  be  made  in  difirerent  sizes  and  kept  on  hand 
for  use  in  this  and  other  styles  of  crown-work  by  means  of  a 
machine  (Fig.  216)  such  as  is  used  by  jewelers  for  forming  cap- 
shaped  pieces  of  gold,  and  in  factories  for  making  copper  car- 
tridges. The  gold  plate,  cut  into  circular  pieces,  is  pressed  through 
a  steel  die-plate,  with  punches  gauged  to  the  holes ;  at  each  punch 
a  small  portion  of  the  gold  is  turned  over,  thus  preventing  its 


GOLD  SEAMLESS  CONTOUR  CROWNS. 


107 


lapping  or  creasing  (Fig.  217).     Repeated  annealing  of  the  metal 
is  very  necessary  in  this  process. 


Fig.  210. 


Methods  of  Contouring  Crowns  constj-ucted  in  Sections. — In  con- 
structing a  crown  in  sections,  the  collar  can  be  first  formed  on  a 


Fig.  21 


Fig.  218. 


mandrel,  then  placed  in  a  mold,  and  bur- 
nished to  the  shape  of  the  sides.  The  pro- 
cess of  its  adjustment  to  the  neck  of  the  root 
is  then  continued  in  the  usual  manner. 

Another  method  is  to  stam[i  or  burnish  up  the  collar  on  a  die 
representing  the  upper  sections  of  a  tooth,  designated  as  the 
middle  and  cervical  third   (Fig.   218).      After  contouring  the 


108 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


collar,  the  cap  is  adjusted  and  soldered  on.      With  a  metallic 
stamping-  plate  (see  page  93)  these  caps  are  quickly  made. 

Process  of  Adjusfment  of  Seamless  Contour  Crowns. — A  superior 
molar — one  of  the  most  difficult  teeth  to  operate  on — will  serve 
as  a  typical  case  to  illustrate  this  process.  The  crown  or  root  is 
first  shaped  and  if  necessary  built  down  with  amalgam,  straight, 
or  tapering  slightly  on  its  sides  toward  the  occluding  surface,  as 
described   at  page    39.      Guided  by  the  shape  of  the  natural 

Fig.  219. 


teeth,  and  measurements  b}^  calipers — a  pair  of  tweezers  with 
a  screw  as  shown  in  Fig.  219  answers  the  purpose — -or  by  a 
plaster  model  of  the  mouth,  a  gold  crown  of  suitable  form  and 
size  is  selected.  The  crown  is  then  slipped  over  the  end  of  the 
prepared  natural  crown  or  root,  and  gently  pressed  and  worked 
straight  upward,  the  gold  at  the  neck  of  the  crown  expanding  to 
the  form  of  the  root  until  the  edge  meets  the  margin  of  the  gum 
(A,  Fig.  220).  A  line  (B)  is  then  marked  on  the  gold  with  a 
sharp-pointed  instrument,  parallel  to  the  margin  of  the  gum. 
Tlie  crown  is  then  removed  and  the  edge  trimmed  off  to  this  mark 


Fig.  220. 


Fig.  221. 


or  even  with  it  (A,  Fig.  221),  using  small  curved  scissors.  This 
process  should  be  repeated,  taking  off  a  little  at  a  time,  until  the 
edge  of  the  gold  meets  the  gum  evenly  at  all  points,  under  the 
free  edge  of  which  it  is  then  pressed  up,  and  if  the  occlusion 
is  correct  a  burnisher  is  passed  around  the  cervical  portion  and 
the  gold  burnished  accurately  to  the  root. 

Although  a  crown  can  usually  be  expanded  on  the  root  to  its 


GOLD  SEAMLESS  CONTOUR  CRO]rNS. 


109 


Fig.  222. 


form  Iq  the  process  of  ailjiistrnent,  the  necks  of  natural  teeth 
vary  so  in  proportion  to  the  size  of  the  crown  that  it  otlen 
becomes  necessary  to  slightl}'  expand  the  gold  at  the  neck  of  a 
contour  crown.  Tiiis  is  quickly  and  easily  done,  without  alter- 
ing or  injuring  the  crown,  as  follows:  Soften  a  mass  of  gutta- 
percha, about  the  size  of  the  crown,  upon  the  closed  ends  of  a 
pair  of  clarap  forceps,  or  an  ap-- 
pliance  of  similar  construction. 
Introduce  the  gatta-percha  inside 
of  the  neck  of  the  crown,  which 
should  be  moistened  to  prevent 
its  adhesion.  Then  withdraw  the 
gutta-perrha,  harden  it  i?i  cold 
water,  and  cut  througli  the  center, 
Ijetweeu  the  points  of  the  forceps. 
By  reinserting  the  points  of  the 
forceps  armed  with  the  gutta-per- 
cha, the  neck  of  the  crown  may 
be  expanded  in  any  direction  ac- 
cording to  the  manner  in  whieh 
the  forceps  and  gutta-percha  have 
l)een  inserted  (Fig.  222).  A  gold 
collar  can  be  expanded  in  a  similar 
manner. 

Before  the  crown  is  pressed  up 
to  its  apparently  proper  position, 
the  ocelusiou  should  be  examined 
and  calculations  carefully  made  to 
obviate  any  defects,  which  at  this 
stage  can  be  readily  corrected  by 
proper  manipulation  of  the  crown.  Any  desirable  change  can 
usually  be  made  in  the  form  of  the  occluding  surface  of  the  crown 
while  on  the  tooth,  with  an  instrument  tapped  by  the  mallet,  or 
by  removing  the  crown,  holding  it  with  the  index  finger  pressed 
flat  against  the  edge  of  the  cervical  portion,  the  other  fingers 
grasping  tlie  sides,  and  tapping  the  gold  with  a  riveting  hammer. 
The  position  can  be  changed  for  altering  the  sides,  on  which 
the  fiat  end  i»f  the  hammer  should  be  used. 


110  ARTIFICIAL  CROWN-  AND  BRIDGE- WORK. 

^Strengthening  Seamless  Gold  Contour  Croirns. — Additional 
strength  and  stiffiiess  can  be  given  to  seamless  gold  crowns 
when  desired,  in  several  ways.  The  liability  of  melting  the 
gold  which  forms  the  sides  of  the  crown  in  the  operation  has, 
with  some,  been  the  principal  objection  to  their  use.  This, 
however,  can  be  avoided.  Where  the  cusps  or  grinding-surfaces 
require  filling  in  or  thickening,  which  is  done  from  the  inside,, 
it  is  safely  accomplished  as  follows  :  Take  a  pellet  of  moldine/ 
moisten  it  with  water,  and  work  it  until  quite  soft,  then  roll  it 
out  lengthwise,  and  envelop  the  crown  on  its  sides  with  a  very 

Fig.  223.  Fig.  224.  Fig.  225. 


<dL!»>, 


thin  continuous  piece,  leaving  exposed  the  parts  of  the  occlud- 
ing surface  that  are  to  be  tilled  in.  Pass  around  on  the  outside 
of  the  moldine,  without  touching  the  crown,  a  fine  wire,  and 
twist  the  ends  together  for  a  handle  (Fig.  223).  Grind  some 
borax  mixed  with  water  to  a  cream-like  consistence,  and  with  a 
small  pellet  of  cotton  twisted  on  an  instrument  paint  the  inside 
of  the  crown  with  the  borax  just  where  you  wish  the  solder  to 
flow.  Then  place  inside  the  cusps  an  easy-flowing  solder  that 
has  been  cut  tine  and  immersed  in  the  borax.  The  crown  is  then 
held  in  the  flame  of  an  alcohol  lamp  or  in  a  blue  gas  flame,  and 
heated  slowly  so  that  the  position  of  the  solder  will  not  be 
changed  by  the  fusing  of  the  borax.  Increase  the  heat  until 
the  solder  flows  over  the  surface  of  the  gold,  which  it  does  very 
quickly  when  the  melting-p()int  is  reached.  Then  the  crown 
must  be  instantly  removed  and  examined.  Sufficient  solder 
should  be  placed  in  the  crown  to  give  it  the  desired  strength  in 
one  heating,  but  in  case  of  necessity  more  can  be  added  and  the 
process  cautiously  repeated.  The  moldine  protects  the  sides, 
which  generally  take  up  the  greatest  degree  of  heat. 


GOLD  SEAMLESS  COXT(fUR  CROWNS.  Ill 

Another  method  for  streiigthenino;  or  tilHng  gold  seamless 
crowns  with  solder  or  even  18-  or  20-carat  gold  plate,  is  to  invest 
the  outside  surface  of  the  crown  in  plaster  and  marble-dust 
(Fig.  224),  and  then  with  a  small  flame  of  the  earbo-oxyhydro- 
gen  blow-pipe,  not  over  one-half  an  inch  in  length,  introduced 
inside  of  the  crown,  melt  and  flow  the  solder  or  gold  plate 
over  any  portion  or  even  all  of  the  surface  of  the  gold.  The 
crown,  if  formed  of  gold  with  a  thin  lining  of  platinum,  can  be 
soldered  by  either  method  with  little  danger  of  being  melted. 

If  for  some  special  purpose  it  is  desirable  to  strengthen  the 
neck  of  a  crown  by  increasing  the  thickness  of  the  gold,  it  is 
first  soldered  to  stiflen  the  occluding  surface  as  above  described, 
the  investing  material  is  then  removed,  and  the  inside  of  the 
crown  filled  solid  with  moldine  or  investing  material.  The  gold 
which  is  dulled  on  the  surface  is  scraped  around  the  crown, 
along  the  line  of  the  cervical  edge  (A,  Fig.  225),  only  as  low  as ' 
the  stiflening  is  required.  Along  this  part,  borax  is  applied  with 
a  brush,  and  small  pieces  of  20-carat  solder  placed  in  succession 
and  melted,  the  crown  being  turned  during  the  process  until  the 
neck  is  entirely  encircled. 

Supporiing  the  Croion. — In  crowning  teeth  with  living  pulps 
there  is  sufficient  of  the  natural  crown  present  to  aftord  a  secure 
foundation  and  attachment  for  the  artificial  crown,  as  is  also  the 
case  with  many  teeth  that  are  pulpless ;  but  in  badly  broken- 
down  crowns,  or  where  only  the  root  is  present,  a  metallic  pin 
or  post  should  be  inserted  in  the  root,  and  the  part 
built  down  with  amalgam  to  a  form  that  will  afford 
secure  support  and  attachment  to  the  artificial  crown, 
and  facilitate  its  adjustment.  (See  "  Special  Prepa- 
raticrn  of  Badly-Decayed  Teeth  or  Roots,"  page  39.) 

In  many  cases  the  required  support  for  the  crowu 
can  be  secured  by  means  of  a  screw  (Fig.  226). 
A  How  screw  is  inserted  in  the  root-canal  A  (see 
page  52).  Amalgam  is  then  packed  in  the  lower 
section  of  the  artificial  crown,  C,  to  the  line  B,  and 
into  the  amalgam  the  screw  is  pressed.  Amalgam  which  has 
been  put  in  a  piece  of  cliamois  and  the  mercury  pressed  out 
with  a  pair  of  pliers  untii  it  is  'In  the  condition  termed  ''  dry  "'' 


112  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

will  adhere  to  the  gold  without  affecting  it.  The  amalgam  is 
first  placed  in  the  crown  slightly  in  excess  of  the  amount  re- 
quired, and  the  crown  adjusted,  removed,  and  the  surplus 
scraped  out.  This  process  is  continued  until  the  screw  or  the 
crown  section  of  the  natural  tooth  forms  an  indentation  in  the 
amalgam,  which  it  will  fit  when  the  crown  is  cemented  on.  The 
vent  for  the  escape  of  air  and  surplus  cement — which  should 
always  be  put  in  perfect-fitting  crowns  and  afterwards  filled  with 
o;old  or  amalo;am — should  be  in  the  line  of  the  indentation  in 
the  amalgam,  with  which  it  must  connect  (D).  (For  process  of 
pementation,  see  article  on  "  Insertion  and  Cementation.") 

These  crowns  can  be  inserted  in  an  easy  and  inexpensive  man- 
ner by  filling  in  the  lower  section  of  the  crown  with  amalgam 
instead  of  gold,  and  allowing  the  head  of  the  screw  or  the  nat- 
ural crown  to  indent  the  amalgam  as  al)ove  described,  and  then 
cementing  on  the  crown  with  oxyphosphate  in  the  usual 
manner. 

In  a  case  so  inserted,  with  no  antagonizing  teeth,  the  result  is 

the  same  as  though  the  inside  of  the  occluding  surface  of  the 

crown  was  filled  with  gold  ;  but  if  antagonizing  teeth  are  present, 

the  soft  gold  of  the  crown  is  apt  to  M'ear  through  in  places  and 

-—expose  the  amalgam. 

If  a  tooth  is  short  and  the  articulation  such  as  to  require  the 

reduction  of  the  collar  to  a  size  which  will  suggest  insecurity 

when   the  crown    is   cemented,  or  if  tlie  tooth   is  pulpless,  a 

headed  or  barbed  pin  that  will  anchor  in  the  root  should 
Fig  227  ..... 

be  soldered  in  the  interior  of  the  crown,  as  shown  in 

Fig.  227.  This  is  done  by  passing  the  pin  through  a 
liole  made  in  the  occluding  surface  of  the  crown,  adjust- 
ing the  crown  in  the  mouth,  removing,  investing,  and 
soldering  the  pin  from  the  outside  surface  of  the  crown. 
The  advantages  of  seamless  contour  crowns  are,  that  they 
represent  perfectly  the  tooth  in  its  anatomical  contour,  present  a 
uniform  surface  of  pure  gold,  which  preserves  its  color  without 
tarnishing,  and  are  quickly  and  easily  adjusted.  Their  defects  are 
inability  to  meet  the  requirements  of  abnormally-shaped  roots 
and  anomalous  ai'ticulations. 


CHAPTER   X. 

GOLD   CROWNS   WITH   PORCELAIN   FRONTS   FOE   TEETH  WITH 

LIVING  PULPS. 

In  the  anterior  teeth,  in  case  of  atrophy  or  erosion,  or  where 
decay  has  destroyed  the  approximal  sides  of  a  tooth  in  such  a 
manner  that  crowning  is  considered  the  most  desirable  operation 
to  perform,  the  pulp  is  frequently  found  unexposed  and  in  a 
normal  condition.  The  importance  of  its  preservation  in  such  a 
case  is  unquestionable. 

Tlie  methods  at  present  most  commonly  used  to  form  a  crown 
under  such  conditions  are  in  many  respects  defective  and 
objectionalile,  notwithstanding  the  advantages  their  indorsers 
claim  for  them. 

In  the  tirst  place,  all  crowns  of  platinum  and  iridium,  with 
body  baked  on  to  represent  the  labial  aspect  of  the  tooth,  have  a 
dead  and  unnatural  appearance,  and  from  those  on  which  jGdms 
of  porcelain  representing  teeth  are  l)aked  the  porcelain  fre- 
quently chips  off,  and  both  styles  usually  protrude  beyond  the 
line  of  the  adjoining  teeth. 

The  method  here  presented  is  intended  to  overcome  these 
objections  and  to  produce  a  more  satisfactory  result.  The  des- 
criptive details  of  the  crowning  of  a  central  incisor  will  serve  to 
illustrate  it.  A  model  is  tirst  made  representing  the  tooth  in  a 
perfect  form.  This  can  be  done  either  by  shaping  the  natural 
tooth  in  the  mouth  with  oxyphosphate  or  gutta-percha,  taking 
an  impression  of  it  in  wax  oi-  moldine,  and  forming  a  model 
in  plaster  or  fusible  alloy,  or  by  taking  a  natural  tooth  and 
shaping  it  to  correspond,  or,  if  the  operator  is  an  expert,  carving 
one  from  a  piece  of  i)laster. 

Two  casts,  one  of  the  coronal  form  of  the  tooth  (Fig.  22H), 
and  the  other  of  only  the  palatal  and  approximal  portions  (Fig. 

8  113 


114 


ARTIFICIAL  CROWN-  AND  BRIDGE- WORK. 


229),  are  made,  using  the  moldine  in  tubes  with  fusible  metaL 
This  will  consume  only  a  few  minutes.  A  piece  of  gold  and 
platinum  crown  plate,  iSTo.  34  U.  S.  standard  gauge,  about  the 
length  and  circumference  of  the  tooth,  is  then  struck  up  on  the 
palato-approximal  cast,  from  which  it  receives  the  palatal  and 
approximal  aspects  of  the  tooth.  It  is  then  transferred  to  the 
coronal  east,  which  is  previously  trimmed  the  thickness  of  the 
gold  plate  upon  the  approximal  surfaces,  and  worked  down  to 
the  exact  form  of  the  tooth  on  the  anterior  portion  (Fig.  230). 
The  metal,  which  is  then  the  exact  form  of  the  tooth  on  all 
sides,  is  cut  even  at  the  incisive  edge,  the  seam  down  the  front 
beveled,  lapped,  and  marked,  then  slightly  opened,  and  the  gold 
slipped  oiF  the  die.      Guided  by  the  mark,  the  gold  is  then 


Fig.  228. 


Fig.  229. 


Fig  2.S0.       Fig.  231.  Fig.  283.     {-^ 

yj! 


U 


Fig.  232. 


pressed  back  to  the  form  assumed  on  the  die,  and  fitted  to  the 
natural  crown,  which  should  have  been  previousl}^  trimmed  and 
shaped  as  described  on  page  38  (Fig.  19),  and  the  joint  on  the 
labial  side  soldered  (Fig.  231).  Into  the  incisive  edge,  which  is 
open,  a  narrow  strip  of  gold,  about  one-sixteenth  of  an  inch  in 
width  and  thick  enough  to  fill  the  space,  is  fitted  and  soldered. 
This  strengthe*is  the  whole  crown,  and  forms  a  protecting  edge 
for  the  porcelain  front. 

We  have  now  a  gold-contoured  crown,  an  exact  imitation  of 
the  tooth  under  treatment.  The  crown  is  then  filled  with 
plaster,  and  the  labial  ]>ortion  ground  and  filed  away,  so  as  to 
leave  the  upper  part  to  form  the  band,  and  the  lower  the  in- 
cisive edge,  as  represented  in  Fig.  232. 

A  porcelain  tooth  which  matches  in  shade  and  form  is  then 
ground  and  thinned  down — in  which  operation  the  pins  are 
removed — to  the  form  of  a  thin  porcelain  front,  thickest  at  the 


GOLD  CROWNS   WITH  PORCELAIN  FRONTS.  115 

incisive  edge.  This  front  is  fitted  to  replace  and  represent  the 
lal)ial  portion.  The  porcelain  is  then  removed  and  a  piece  of 
platinum  foil  adapted  to  its  back,  and  turned  just  barely  over 
the  edges,  the  upper  and  lower  of  which  should  be  slightly 
tapered  off,  as  shown  in  Fig.  233. 

The  platinum  can  be  made  to  lit  closely  to  the  porcelain  by 
rubbing  the  edges  on  a  piece  of  cloth  or  chamois,  on  a  Hat 
surface.  The  porcelain  front  is  then  adjusted  on  the  crown 
and  cemented  on  one  side  with  wax,  and  the  crown  invested  in 
plaster  and  marble-dust,  so  that  the  seam  along  the  edge  of  the 
platinum  and  gold  is  exposed  on  the  cemented  side  and  at  one 
end  as  shown  in  Fig.  234.  The  investment  is  then  heated  and 
the  seam  soldered  with  small  pieces  of  20-carat  solder.  Care 
must  be  taken  not  to  flow  the  solder  upon  the  porcelain,  or  to 

Fig.  234.  Fig.  235.  Fig.  236.  Fig.  237. 


use  more  borax  than  is  absolutely  necessar}',  as  otherwise  the 
porcelain  will  be  fractured. 

When  the  investment  is  cold,  the  crown  is  removed,  again 
invested,  and  the  remainder  of  the  seam  soldered,  or  the  invest- 
ment <.-iu\  be  immediately  removed  from  the  other  side,  and  the 
soldering  completed ;  though  this  latter  plan  is  attended  with 
some  risk  to  the  porcelain. 

After  the  crown  has  gone  through  the  finishing  process,  the 
excess  of  porcelain  inside  of  the  crown  is  ground  away  in  a  few 
minutes  with  a  small  piece  of  corundum  melted  on  an  old  oval- 
shaped  bur.  The  cavity  in  the  crown  is,  meanwhile,  kept  filled 
with  water  (Fig.  235). 

In  adjusting  the  crown,  tlie  natural  tooth  can  be  smeared  with 
articulating  [)aste,  which  will  easily  indicate  any  point  obstruct- 
ing its  perfect  adaptation.  When  fitted,  the  crown  is  attached 
witli  oxy phosphate  .cement.  Fig.  236  shows  the  completed 
I'rown. 


116 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


Fig.  238. 


Bicuspids  and  molars  can  be  made  in  the  same  manner  by 
using  a  contour  crown  of  gold  lined  with  platinum  (see  chapter 
on  contoured  crowns),  and,  after  its  adjustment,  fill- 
ing in  the  crown  with  plaster,  and  then  cutting  aAvay 
the  labial  portion  and  replacing  it  Avith  p)orcelain 
(Fig.  237). 

Croirnin'/  in  Cases  <if  Ahi'dskm. — In  a  case  of  ex- 
tensive abrasion  of  the  incisive  edges  of  the  antei'ior 
teeth,  with  pulp  living  though  considerably  calcified 
in  the  coronal  section,  crown-work  to  restore  the 
length  and  form  of  the  teeth  is  best  performed  by 
removing  a  portion  of  the  labial  aspect  of  the  natural 
crown  and  then  forming  the  artificial  crown  similar 
to  a  gold  collar  crown  without  the  pin.  An  accurately  adapted 
collar,  cemented  with  oxyphosphate,  will  secure  the  crown  suffi- 
ciently. Fig.  238  gives  an  outline  of  the  construction  of  such  a 
crown. 


CHAPTER    XL 

SPECIAL  FORMS  OF  GOLD  CROWNS  WITH  PORCELAIN  FRONTS. 
THE   PARR   CROWN. 

This  crown,  which  in  form  of  construction  possesses  special 
points  of  merit,  is  largely  used  by  Dr.  H.  A.  Parr. 

The  root  is  prepared,  banded,  and  capped  without  a  pin,  the 
same  as  for  a  gold  collar  crown  (A,  Fig.  239).  A  hole  is  made 
in  the  cap,  and  a  post  fitted  in  tlie  canal.  A  piece  of  gold  plate, 
fully  the  size  of  the  cap  on  the  root,  is  adjusted  on  the  post 
above  the  cap  by  making  a  hole  in  the  gold  in  which  the  post 
will  fit  tightly.     The  gold  plate  is  then  adapted  to  the  cap  on  the 


Fig.  239. 


Fig.  240. 


Fig.  241. 


root,  and  burni.shed  into  any  open  ,-pace  around  the  post, 

forming  an  outside  cap ;  the  pin  and  the  outer  cap  are 

then  removed  and  soldered  together  and  adjusted  on 

the  inner  cap,  and  the  edge  of  the  outer  cap  trimmed  even  with 

it  (B).     The  porcelain  tooth  to  form  the  crown,  C,  is  fitted  and 

attached  to  the  outer  cap,  which,  when  finished,  is  cemented 

in  position  as  shown  in  Fig.  240. 

The  advantage  of  this  form  of  crown  is  that  the  root  is 
securely  and  permanently  capped  independently  of  the  crown, 
which  can  be  removed  without  disturbing  the  cap  on  the  root. 

117 


118 


ARTIFICIAL  CROWN-  AND  BRIDGE- WORK. 


Fig.  242. 


Dr.  Parr,  in  using  this  style  of  crown  in  bridge-work,  constructs 
the  outer  cap  with  a  band  which  half  encircles  the  inner  cap, 
and  tapers  off  from  the  palatal  to  the  labial  section,  as  illustrated 
in  Fig.  241.  The  cap  on  the  root  is  cemented  with  oxy phos- 
phate, and  the  post  and  outer  cap  with  gutta-percha. 

THE    LEECH    CROWN. 

Dr.  Leech's  crown  is  thus  described  bv  Dr.  J.  E.  Dexter:' 
"A  method  devised    by  Dr.  H.  K.  Leech,  of  Philadel]>hia, 

shown  in  Fig.  242,  and  described  in 
the  Denial  Cosmos  for  April,  1879,  is 
as  folloAvs  :  The  root  is  drilled  out  to 
a  depth  of  about  three-eighths  of  an 
inch  to  a  diameter  of  about  jSTo.  16, 
standard  (American)  wire  gauge,  the 
bottom  of  the  hole  being  flared  or 
enlarged,  and  the  canal  above  tilled 
with  gutta-percha.  A  gold  tube  is 
made  to  fit  the  hole  accurately  and 
project  sufficiently  for  convenience  of 
handling,  and  is  soldered  throus;!!  a  hole  in  a  iJ-old  base  struck 
to  the  root,  projecting  through  the  plate  some  distance.  A  plate 
tooth  is  fitted  to  the  root  and  plate  and  soldered  to  the  latter, 
gold  being  flowed  onto  the  plate  and  backing  and  around  the 
projecting  tube  to  form  the  palatal  contour,  and  the  tube  cut  ott" 
flush  with  the  latter.  We  now  have  a  plate  tooth,  gold  backed, 
with  a  tube-pivot,  the  orifice  of  which  opens  on  the  })alatal 
aspect  of  our  tooth.  The  root-end  of  the  tube  is  now  slit  per- 
pendicularly in  three  pr  four  places,  for  about  two-thirds  of  its 
length,  a  thin  sheet  of  warmed  gutta-percha  is  placed  on  the 
base  of  the  croAvn  around  the  tube,  and  the  whole  is  pushed 
securely  to  place.  Now  pack  gold  or  tin  into  the  tube,  coiv/enmif/ 
the  bnUoin  j)OrHoris  so  fhut  the  slit  end  irill  spread  and  Hf/Jdly  Jdf  f/ic 
flared  end  of  the  Inile  in  Ike  root,  and  the  operation  is  complete." 

A  collar  crown  fastened  with  a  tube-pivot  as  described  can  be 
used  to  advantage  in  detachable  bridge-work,  as  the  tube  if 
filled  with  tin  foil  will  admit  of  the  crown  beiiiii'  easily  detached. 


^Denial  Cosmo.",  May,  1883. 


THE  LOW  CROWN. 


119 


THE    LOW    CROWN. 


In  the  method  for  crowninti'  pnli»less  roots  of  Dr.  J.  E.  Low, 
of  Chicau'O,  the  root-eaual  is  reamed  out  with  an  instrument 
which  at  the  same  time  shapes  the  end  of  the  root,  or  a  portion 
of  it,  to  receive  a  combined  post  and  cap,  which  the  inventor 


Fig.  243. 


Fig.  244.     Fig.  245.     Fig.  246. 


calls  a  "  step-plug,"  from  its  peculiar  form.  There  are  seven 
sizes  of  the  cutting  instruments  (Fig.  243),  and  corresponding 
exactly  with  them  seven  sizes  of  the  step-plugs.  These  stej)- 
plugs  are  not  unlike  a  minute  cone-})ulley  set  in  a  saucer-shaped 
cap  upon  the  bottom  of  which  is  a  stout  boss.  They  are  nuide 
of  platinum  and  nickel.  As  these  last  lit  the  ]U'epared  root 
accurately,  it  is  claimed  that  they 
afford  a  secure  foundation  for  the 
artiiicial  crown  and  also  jircveut 
longitudinal  fracture  of  the  root. 

To  describe  and  illustrate  the  ])ro- 
cess,  the  root  of  a  central  incisor  (Fig- 
244)  is    selected.     The    end    of  the 

root  is  first  ground  level  with  the  |)alatal  margin  of  the  gum.  A 
cutting  instrument  of  suitable  size  is  then  selected,  with  which 
the  root  is  shaped  as  shown  in  Fig.  245.  The  end  of  the  root  is 
removed  enough  to  permit  the  palatal  edge  of  the  cap  of  the  step- 
plug  (Fig.  246).  which  is  then  adjusted,  to  pass  just  below  the 


120 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


margin  of  the  gum.  Fig.  247  shows  the  step-plug  in  position,  and 
ready  for  the  adjustment  of  the  porcelain  front  (Fig.  248)  and 
the  construction  of  the  crown,  which  is  completed  as  in  methods 
previously  described.  The  porcelain  front  when  adapted  should 
meet  the  labial  margin  of  the  gum,  and  when  necessary  the 
lalnal  surface  of  the  end  of  the  root  should  be  trimmed,  with 
the  cap  in  position,  with  a  corundum-wheel  to  permit  it.  When 
the  porcelain  front  is  to  l)e  adjusted  in  the  mouth,  the  backing 
should  be  warmed,  a  small  quantity  of  resin  and  wax  cemented 
u})on  it,  the  tooth  placed  in  position  in  the  mouth,  and  the  con- 
vex surface  of  the  step-plug  cap  perfectly  imbedded  in  the  wax. 
The  wax  and  the  porcelain  front  should  next  be  carefully  removed 


Fig.  247. 


Fig.  250. 


Fig.  252. 


Fig  254. 


Fig.  251. 


Fig.  253. 


Fig.  255. 


and  then  the  step-plug,  using  pliers  for  the  last.  The  step-plug 
is  then  to  be  placed  in  the  Avax  impression,  to  which  it  is  fixed 
with  a  heated  s})atula,  and  then  invested  for  soldering.  Fig.  249 
shows  the  completed  crown  ready  for  final  adjustment,  and  Fig. 
250  gives  a  sectional  view  of  it  in  position. 

In  crowning  bicuspid  roots,  one  step-plug  placed  in  the 
palatal  side  of  the  root  (Fig.  251)  is  usuallj^  sufficient,  the 
remaining  exposed  surface  of  the  end  of  the  root  being  covered 
by  adapting  thin  platinum  plate  over  it  and  on  to  the  surface  of 
the  cap  before  adjusting  the  porcelain  front  (Figs.  252  and  253). 
Figs.  254  and  255  show  the  completed  bicuspid  crown  before 
and  after  the  final  adjustment.  Molar  roots  are  capped  in  a- 
similar  manner,  using  two  step- plugs. 

The  plugs  are  useful  in  building  up  badly-decayed  roots  to 
support  and  retjiin  all-gold  crowns. 


CHAPTER    XII.    ■ 

CROWNING  FRACTUKED  TEETH  AND  ROOTS,  AND  IRREGULAR 

TEETH. 

The  crowning  of  fractured  teeth  and  roots  is  a  process  that 
requires  skill  and  delicate  treatment.  Its  practicability  depends 
on  the  nature  of  the  fracture,  the  previous  health  of  the  parts, 
and  the  length  of  time  that  has  elapsed  since  the  occurrence 
of  the  injury. 

LONGITUDINAL    FRACTURE    OF    THE    CROWN    AND    ROOT. 

B}^  this  is  meant  a  fracture  of  the  crown  or  what  remains 
of  it,  longitudinally  through  it,  and   down   the    root   or  roots. 
Foreign  substances  having  been  removed  from  within  and  around 
the   parts,  the   crevice   of  the  fracture  is  syringed  thoroughly 
with  a  solution  of  carbolic  acid  and  tepid  water.     The  fractured 
parts  of  the  root  are  then  drawn  together  with  waxed  floss  Fig.  2o6. 
silk,  passed  at  least  twice  around  the  tooth,  and  tied,  the    -^J^T^^ 
ends  being  passed  through  twice  in  forming  the  knot.      J^J 
The  pulp-chamber  is  then  prepared,  and  dovetail  slots    ^>— — ^ 
drilled  across  the  parts  (Fig,  256).    If  it  is  suspected  that  any  of 
the  particles  removed  in  the  preparation  have  invaded  the  crevice 
of  the  fracture,  the  ligature  must  be  removed,  the  parts  again 
syringed,  and  the  ligature  readjusted.     The  upper  parts  of  the 
root-canals  are  then  tilled  with  gutta-percha,  and  the  main  body 
of  the  cavity  and  the  slots  with  a  hard,  quick-setting  amalgam. 
At  the  next  visit  of  the  patient  the  ligature  is  removed  and  the 
parts  carefully  prepared  for  crowning.     The  circumference  of 
the  root  is  lirst  measured  with  a  wire,  a  tight-fitting  collar  con- 
structed, and  the  crown  then  completed  in  the  usual  manner. 

The  great  drawback  in  these  cases  is  that  the  patient  generally 
fails  to  present  himself  immediately  for  treatment,  and  foreign 
substances  work  into  the  fracture,  causing  inflammation,  which 

121 


122 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


is  difficult  to  control.  Often  sul)se(j[uent  to  treatment  a  septic 
condition  of  the  fracture  supervenes,  the  irritation  caused  thereby 
and  the  exudations  from  the  fracture  becoming  so  annoying  that 
extraction  is  the  only  alternative. 

Teeth  fractured  as  above  descril)ed  rarely  have  living  pulps. 

FRACTURE  OF  THE  CROWN,  WITH  SLANTING  FRACTURE  OF 

THE  ROOT. 

Fractures  of  this  kind  are  common,  especially  in  bicuspids, 
where  large  fillings  are  inserted  extending  from  the  anterior  to 
the  posterior  approximal  walls,  leaving  the  separated  buccal  and 
palatal  cusps  to  bear  the  force  in  mastication. 

In  such  cases  the  fracture  seldom  extends  beyond  the  edge  of 
the  alveolar  process.     The  fractured  part  having  been  removed, 


Pig.  257. 


Fig.  258. 


Fig.  259. 


a  dovetail  slot  is  made  in  the  crown  or  root,  into  which  gutta- 
percha is  inserted  for  a  day  and  the  membrane  of  the  gum  pressed 
back,  so  as  to  fully  expose  the  surface  of  the  fracture.  The  form 
of  the  root  is  then  in  a  measure  restored  with  amalgam,  which, 
when  hard,  is  polished  (Figs.  257  and  258). 

The  root  is  then  crowned  tlie  same  as  in  any  other  case. 


METHODS   OF  CROWNING   IN   CASES   OF   IRREGULARITY. 

Fig,  259  shows  a  method  of  treating  a  case  of  irregularity 
without  destroying  the  vitality  of  the  pulp.  The  tooth  at  B, 
which  stood  inside  the  line  of  the  lower  teeth  when  the  mouth 
was  closed,  was  trimme<I,  shaped,  and  capped.     To  this  cap  was 


CROWNING  IN  CASES  OF  IRREGULARITY. 


1-23 


attached  the  tooth  at  A,  with  an  oval-sha]:»ed  piece  of  gold  that 
cleared  the  lower  teeth  in  occlusion.  The  cap  was  then  cemented 
to  the  natural  crown. 

Fig.  260  represents  a  case  of  irregularity  treated  by  Dr. 
Bonwill,  who  says  in  his  description  of  it, — 

''  This  shows  a  case  of  irregularity  which  was  beyond  correc- 
tion, on  account  of  the  poor  character  of  the  teeth,  their  position 
in  the  palatal  arch,  and  the  age  of  the  patient.     In  such  cases  I 

Fig.  260. 


do  not  hesitate  to  cut  otf  the  crown,  destroy  the  pulp,  and  place 
one  of  the  plate  tooth-crowns  with  a  nut.  To  do  so,  the  crown 
must  be  connected  to  the  root  by  a  strip  of  heavy  gold  plate, 
extending  for  one-quarter  of  an  inch  or  more,  to  bring  the  artificial 
crown  into  the  circle.  For  such  cases  the  porcelain  crown  will 
also  answer." 


CHAPTER  XIII. 

PAETIAL  CEOWNS. 

Gold. — Partial  crowns  of  gold  for  the  protection  of  plastic 
fillings  in  large  cavities  and  for  the  restoration  of  contour  are 
often  desirable  when,  for  any  reason,  a  solid  metallic  filling  cannot 
well  be  inserted.     The  cavity  having  been  properl}^  excavated, 
its  orifice  is  trimmed  as  uniformly  straight  or  circular  as  its 
position  and  character  -will  allow,  and  the  edge  of  the  enamel 
beveled  off",  tapering  towards  the  center.     In  the  preparation  of 
cavities  in  the  grin  ding-surface,  trimming  and  cutting  away  the 
enamel   should   be   confined   to   that   surface.     In   approximal 
cavities   which    reach   the   grinding-surface,   it   is  advisable  to 
extend  them  in  that  surface  and  bring  the  gold  over 
Fig.  261.     and  anchor  it  there,  so  as  to  afiibrd  greater  security 
against  its  displacement  in  mastication.      "Where  de- 
cay extends  close  to  the  margin  of  the  gum,  if  the 
tooth  is  trimmed  away  so  that  the  gold  will  extend  just 
under  its  free  edge,  a  recurrence  of  decay  at  that 
point  will  be  avoided.     The  bicuspid  shown  in  Fig.  261  will 
serve  as  a  typical  case  to  illustrate  the  constructive  details. 

The  cavity  having  been  properly  prepared,  a  die  of  the  tooth 
in  its  original  form  is  then  secured.  For  this  purpose  the  mold 
is  made  by  taking  an  impression  of  the  tooth  with  wax,  making 
a  plaster  model,  and  then  restoring  the  contour  and  forming 
from  it  the  mold  in  gutta-percha  or  moldine ;  or  the  shape  of  the 
natural  tooth  may  be  restored  with  wax  or  gutta-percha  and  the 
iiiokl  made  directly  from  it  in  plaster.  The  die  and  counter- 
die  having  been  formed  (see  article  on  "  Molds  and  Dies  "),  a 
piece  of  pure  gold,]Sro.  28  to  30  standard  gauge,  the  exact  thickness 
being  governed  by  the  size  and  nature  of  a  cavity,  is  struck  up  to 
the  form  and  size  of  the  part  to  be  capped.  The  gold  is  then 
124 


PARTIAL  CROWNS. 


125 


Fig.  262. 


Fig.  263. 


adjusted  to  the  cavity,  and  the  edges  trimmed  and  hurnished 
tf>  fit  close  and  flush  with  the  edges  of  the  cavity.  In  the  case 
of  large  cavities  including  a  part  or  the  whole  of  the  approximal 
surface,  a  model  of  the  tooth  and  the  empty  cavity  from  an  impres- 
sion taken  in  wax  will  sometimes  facilitate  and  guide  the  pre- 
liminary trimming  and  shaping  of  the  gold.  Two  headed  pins 
fixed  on  the  inside  of  the  cap  (Fig.  262)  are  generally  sufficient 
to  secure  it,  but  others  can  be  added  if  the  con- 
ditions of  the  case  seem  to  require  it.  In  com- 
pound cavities,  including  the  side  and  grinding- 
surface,  one  pin  at  least  should  be  fixed  in  the 
latter  portion.  A¥here  the  grinding  and  both 
approximal  surfaces  are  included,  a  wire  should 
be  extended  from  one  side  to  the  other  (Fig.  263), 
but  the  fastening  should  not  touch  the  bottom  of 
the  cavity. 

In  pulpless  teeth  the  pin  from  the  upper  part  of 
the  cap  should  extend  up  the  canal,  giving  great 
stability  in  such  cases  (Fig.  264). 

In  soldering  the  pins  or  loops  when  inserted  in 
holes  drilled  in  the  gold,  a  little  solder  can  be  flowed 
over  the  adjacent  parts  if  deemed  necessary  to 
stiffen  and  strengthen  them. 

Oxyphosphate  is,  as  a  rule,  the  best  to  be  used 
in  connection  with  these  caps,  as  it  forms  a  solid 
and  unyielding  foundation,  ynd,  when  properly 
protectfd  from  the  fluids  of  the  mouth  by  a  care- 
fully adjusted  cap,  is  very  durable. 

The  cement  should  be  first  inserted  in  the  cavity, 
and  then  a  small  quantity  placed  around  the  pins 
of  the  cap,  which  should  be  immediately  adjusted  accurately 
in  position.  When  gutta-percha  is  used,  it  is  heated  and  applied 
in  the  same  manner  to  cavity  and  cap.  The  cap  is  then  heated, 
pressed  into  position,  and  held  there  until  the  gutta-percha 
hardens.  This  can  be  hastened  by  the  application  of  cold 
water  from  a  syringe.  The  surplus  of  gutta-percha  is  then 
removed,  and  the  edges  of  the  gold  burnished. 

These  caps  applied  to  cases  with  living  pulps  show  durability 


Fig.  264. 


126 


ARTIFICIAL  CROW 2^-  AND  BRIDGE-WORK. 


of  a  commendable  character.  The  advantage  they  possess  over 
pieces  of  porcelain  is  found  in  the  close  joint  that  can  be  made 
with  the  edge  of  the  enamel  by  burnishing  the  gold  against  it. 

Porcelam  and  Gold. — The  partial  restoration  with  porcelain  and 
gold  of  an  incisor  crown  such  as  is  shown  in  Fig.  265  is  often  desir- 
able. The  edges  of  the  crown  to  form  the  joining  with  the  porce- 
lain are  trimmed  straight  and  level,  and  then  polished.  A  shallow 
groove  is  generally  formed  to  advantage  at  A,  Fig.  266.     A  very 


Fig.  265 


Fig    266. 


Fig.  267. 


Fig.   268 


Fig    269. 


Fig    270. 


thin  piece  of  plaiinum  is  then  adapted  to  the  crown  as  shown  at  B, 
Fig.  267.  The  pin  C  is  fitted  to  the  root-canal,  passing  through 
the  platinum.  The  post  and  cap  of  platiniun  are  then  attached 
with  wax,  removed,  invested,  and  soldered  with  pure  gold.  A 
little  of  the  gold  at  the  same  time  is  flowed  over  the  cap.     The 

cap  and  post  are  then  adjusted  to  the 
crown,  and  the  cap  is  trimmed  level 
and  burnished  so  that  it  fits  closely 
against  the  surface  of  the  fracture 
and  into  the  groove  at  A,  Fig.  266. 
At  this  stage  of  the  work,  to  facilitate 
the  subse(|uent  operations,  an  im- 
pression can  be  taken  that  Avill  re- 
move in  it  the  cap,  and  from  this  a 
model  can  be  made.  A  cross-pin 
porcelain  tooth  is  then  ground  down  to  a  size  and  shape  that 
will  properly  restore  the  part  and  form  an  accurate  joint  with 
the  labial  edge  of  the  natural  crown.  The  porcelain  is  then 
backed,  cemented  to  the  cap,  removed,  and  soldered  wdth  20-carat 
solder.  The  partial  crown  when  properly  finished  is  cemented 
in  position  with  oxy phosphate. 

In  a  case  such  as  is  represented  in  Fig.  268  the  cap  is  shaped 


PARTIAL  CROU'XS.  127 

to  the  surface  of  the  fracture  at  A  and  o\er  its  palatal  edge,  and 
the  backing  on  the  porcelain  is  extended  out  over  the  palatal 
edge  of  the  fracture  at  B.  The  two  sections  of  the  platinum 
are  united  in  the  soldering. 

Fig.  269  illustrates  a  fractured  central  incisor  in  which  the 
pulp  was  not  exposed,  restored  with  [»orcelain  by  Dr.  J.  Bond 
Littig,  of  New  York.  The  cap  to  the  fractured  part  was  fastened 
by  three  small  pins  as  shown  in  Fig.  270,  which  illustrates  the 
details  of  the'  construction. 


CHAPTER  XIV. 

FINISHING    AND    POLISHING— PROCESS    OF    CEMENTATION. 
FINISHING    AND    POLISHING    CROWN-WORK. 

The  finishing  should  be  done  with  small  corundum-wheels 
and  points,  first  coarse,  then  fine,  on  the  dental  engine,  which, 
for  this  part  of  the  work,  is  preferable  to  files  or  the  lathe.  In 
the  final  finishing  use  moose-hide  points  with  fine  pumice  on 
the  engine,  or  felt  wheels  on  the  lathe ;  and,  in  the  polishing,  a 
brush  wheel,  with  whiting  and  rouge  on  the  lathe. 

The  gold  should  first  be  properly  shaped,  which  includes 
trimming  the  collar  ofif  to  a  fine  edge  where  it  fits  under  the 
gum,  so  that  the  seam  of  union  with  the  root  will  be  impercep- 
tible. The  gold  that  has  been  placed  on  the  incisive  edge  of  the 
incisor  and  cuspid  crowns  should  be  trimmed  away,  so  that 
although  it  will  protect  the  porcelain,  very  little  if  any  will  be 
seen  when  the  crown  is  in  position  in  the  mouth. 

INSERTION     AND    CEMENTATION. 

In  the  insertion  and  cementation  of  all  crown-  and  bridge-work, 
the  object  to  be  eftected  is  the  same  in  principle,  that  is,  to  form 
with  an  insoluble  material  a  solid,  substantial,  and  impervious 
union  between  the  natural  tooth  or  root  presented  and  the  arti- 
ficial crown.  As  a  cement  for  this  purpose,  the  plastic  oxyphos- 
phate  of  zinc  is  generally  i)referred,  and  it  is  in  many  respects 
one  of  the  most  desirable  to  be  found. 

Exact  scientific  proportions  of  the  chemical  substance  of  which 
the  cement  is  composed  are  essential  in  its  preparation,  and  the 
oxide  of  zinc  should  be  in  a  very  fine  povT'der.  A  standard  pre- 
paration of  the  cement  should  be  selected.  For  all  styles  of  crowns 
with  collars,  and  for  bridge-work  depending  on  crowns  of  similar 
con.struction,  slow-setting  cement  should  be  used,  but  for  crowns 
128 


INSERTION  AND  CEMENTATION.  129 

without  a  ferrule  or  collar  the  ordinary  cement  is  preferable. 
For  mixing  the  cement,  a  piece  of  plate-glass  about  five  inches 
long  and  three  inches  wide  as  a  slab  and  a  small  spatula  are 
most  suitable.  The  surface  of  tlie  slab  mu^t  be  perfectly  clean. 
The  acid  and  powder  should  first  be  separately  placed  on  the 
glass,  the  amount  of  powder  being  fully  ec^ual  to  the  requirements 
of  the  acid.  Should  it  be  found  during  the  mixing  that  the  pro- 
[»ortion  of  powder  is  too  great,  the  surplus  should  be  instantly 
thrown  off  the  slab  and  the  mixing,  which  must  l)e  rapid  and 
thorough,  continued;  the  consistence  should  be  that  of  thick 
cream.  If  the  slab  is  placed  on  a  towel  which  has  been  saturated 
with  ice-water,  the  cold  will  retard  the  setting. 

Fig.  271. 


The  parts  to  be  crowned  should  be  previously  syringed  with 
water,  then  protected  by  a  napkin,  bathed  with  alcohol  applied 
by  cotton  with  tweezers,  and  wiped  with  bibulous  paper.  Each 
cap  or  crown,  which  should  have  been  thoroughly  dried,  is  first 
tilled  with  enough  cement  to  insure  a  slight  surplus.  A  small 
portion  is  then  put  in  each  root-canal  or  hollow  part  of  a 
natural  crown  present,  and  tlie  artificial  crown  or  bridge  im- 
mediately adjusted  in  position.  In  many  cases  it  is  best  to 
quickly  remove  the  napkin  and  occlude  the  teeth  to  insure  the 
occlusion,  and  then  open  the  mouth  and  replace  the  napkin.  The 
crown  or  bridge  should  be  held  under  a  slight  pressure  until 
the  cement  sets.  For  this  purpose  a  piece  of  wood  notched  on 
the  end  or  an  adjuster  (Fig,  271)  can  be  used. 

AVhen  the  cement  has  set  perfectly  hard,  the  surplus  around 
the  edges  should  be  removed.  In  collar  or  shell  crowns 
the  edges  of  the  gold  of  the  collar  or  shell  should  be  given 
a  final  burnishing.  AVet  floss  silk  or  dental  fiber,  charged 
with  pumice,  should  be  passed  between  and  around  the  teeth  to 
remove  every  particle  of  the  superfluous  cement,  and  finally  the 
parts  should  be  syringed  with  tepid  water. 

9 


130  ARTIFICIAL  CROWN-  AND  BRIDGE- WORK. 

The  patient  sLould  be  requested  to  call  in  a  few  days,  so  that 
an  examination  may  be  made  to  see  if  any  particles  of  the 
cement  were  overlooked.  Cleansing  gently  at  this  time  facili- 
tates the  healing  of  the  gum  around  the  collar  or  neck.  Care 
in  these  little  details  tends  to  prevent  that  inflamed  appearance 
and  recession  of  the  gum  often  seen  around  crowns,  and  also 
insures  a  satisfactory  result  to  the  patient  and  commendation  to 
the  dentist. 

Previous  to  insertion  the  posts  of  crowns  should  be  slightly 
barbed.  In  all-gold  cap  crowns  a  vent  for  the  escape  of  air  and 
surplus  cement  is  usually  made  in  the  form  of  a  small  hole  in 
the  deepest  fissure  of  the  grinding-surface.  When  the  cement 
is  hard  the  hole  must  in  all  cases  be  closed  with  a  gold  or  amal- 
gam filling. 

When  gutta-percha  is  used  for  cementing,  the  cavity  in  the  root 
and  crown  having  been  moistened  with  chloroform  and  then 
dried  and  heated  by  a  hot-air  syringe,  a  portion  of  the  gutta- 
percha is  inserted  and  caused  to  adhere  to  the  sides.  The  post 
and  the  crown  are  then  heated,  the  proper  quantity  of  the  gutta- 
percha attached,  and  the  crown  inserted.  When  the  gutta-percha 
is  cold,  the  surplus  is  removed  with  a  sharp  instrument,  and 
the  edges  smoothed  by  drawing  back  and  forth  against  them 
some  twisted  fibers  of  cotton  saturated  with  chloroform.  In  some 
cases  the  post  can  be  fastened  with  oxyphosphate  and  the  end  of 
the  root  and  artificial  crown  joined  with  gutta-percha.  The  order 
of  the  use  of  these  materials  can  be  reversed  where  it  may  be 
desirable  at  some  future  time  to  easily  remove  the  crown. 
Bridge-work  can  be  conveniently  attached  temporarily  with  gutta- 
percha. In  this  event  a  quantity  barely  sufficient  to  fasten  the 
caps  should  be  used.  Gutta-percha  does  not  possess  sufi&cient 
rigidity  for  general  use  in  bridge-work. 


PART   III 
BRIDGE-WORK. 


BRIDGE-WORK. 


The  artificial  replacement  of  the  loss  of  a  portion  of  the  teeth 
by  bridging  the  vacant  spaces  with  substitutes,  supported  in  posi- 
tion by  means  of  their  attachment  to  adjoining  or  intervening- 
natural  teeth,  is,  as  we  have  seen  in  the  introduction,  of  antique 
origin,  having  been  practiced  long  before  plates  came  into  use. 

Originally,  the  application  and  mechanical  construction  of 
Fig.  272.  Fig.  273. 


such  dentures  was  of  a  most  primitive  character ;  and  as  the 
attachments  were  simply  ligatures  or  clasps  of  gold,  the  teeth 
were  more  ornamental  than  useful.  Figs.  272,  273,  and  274 
illustrate  the  anti(|ue  methods.^ 

Dentures  constructed  on  the  1-10.2/4. 

bridging  plan  by  various  meth- 
ods have  been  occasionally  em- 
ployed from  the  earliest  days  of 
modern  dentistry,  though  until 
quite  recently  the  system  has 
not  obtained  general  recognition  nor  been  extensively  practiced. 

Dental  literature  presents  bridging  operations  as  described  by 

^See  Independent  Practitioner,  vols,  vi  and  vii,  "  Evidences  of  Prehistoric  Den- 
tistry," by  J.  G.  Van  Marter,  D.D.S.,  Rome,  Italy.     Figs.  272,  273,  274  are  copies 

of  the  illustrations. 

183 


134 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


J.  B.  Gariot  in  1805,  C.  F.  Delabarre  in  1820,  Dr.  S.  S.  Fitch  in 
1829,  and  Dr.  W.  H.  Dwinellc  in  1856.  Fi^-s.  275  and  276 
are  copies  of  illustrations  in  Dr.  Fitch's  work,  published  in 
New  York  in  1829.  In  1871  the  bridging  process  or  bridge 
principle  was  again  brought  to  notice  by  a  patent  applied  for  in 
England  by  Dr.  B.  J.  Bing,  of  Paris,  for  an  improved  means  of 
supporting  and  securing  a  bridge  by  anchoring  with  cement  or 
fillings  clasps  or  bars  extending  from  it  into  holes  formed  in  the 
adjoining  teeth  (Fig.  277).  The  system  was  also  practiced  in 
operations  by  the  late  Dr.  M.  H.  Webb,  and  is  described  in  his 
"  iSTotes  on  Operative  Dentistry." 

The  facilities   aflbrded   by  the  artificial  crown-work  now  in 
vogue  for  supporting  and  securing  bridge-dentures  have  caused 

Fig.  275.  Fig.  276.  Fig.  277. 

C    C      Ct   O^    (Z  o   o 


a  revival  of  the  system  in  an  improved  form,  termed  "  Bridge- 
Work,"  in  which  artificial  crowns  cemented  to  natural  teeth  or 
roots  are  employed  as  abutments  to  support  artificial  teeth  which 
span  or  bridge  the  spaces  between  them.  These  bridges  are  so 
devised,  in  the  best  methods,  that  while  supplying  the  patient  with 
the  means  of  masticating  his  food  the  cleanliness  of  the  denture  is 
also  provided  for. 

Ordinarily,  bridge-work  is  immovably  cemented  in  position. 
The  claims  set  up  in  its  favor  are  as  follows : 

First.  The  perfect  replacement  of  lost  teeth  by  artificial  ones, 
and  without  the  use  of  a  plate. 

Second.  The  absence  of  any  mechanical  contrivance  to  inter- 
fere with  the  tongue  in  articulation. 

Third.     The  functions  of  the  sense  of  taste  are  more  perfectly 


BRIDGE-WORK.  135 

performed,  and  a  healthy  condition  of  the  tissues  preserved, 
because  the  gums  and  palate  are  not  covered  over  with  a  plate. 

Fourth.  The  solidity  and  immovability  of  the  denture  at  all 
times,  both  in  speech  and  mastication. 

Fifth.  Its  special  adaptation  to  the  replacement  of  single 
teeth,  or  of  a  small  number,  where  bridge-work  is  usually 
superior  to  any  other  device. 

Sixth.  AVhile  all  operations  performed  for  the  restoration  of 
lost  teeth,  like  other  remedial  operations,  are  temporary  rather 
than  permanent  in  their  results,  bridge-work  as  regards  per- 
manency takes  equal  rank  with  any  other  operative  procedure. 

The  following,  on  the  other  hand,  are  the  objections  raised 
against  bridge-work: 

First.  It  fails  to  restore  the  contour  of  the  soft  tissues  above 
the  bridge,  as  artificial  gums  cannot  properly  be  used  in  this  style 
of  work. 

Second.  The  slots  beveled  under  the  artificial  teeth,  called 
self-cleansing  spaces,  fill  with  particles  of  food. 

Third.  The  speech  of  the  Avearer  is  often  afitected  by  these 
self-cleansing  slots  under  the  front  teeth. 

Fourth.  If  an  extensive  bridge  is  made  of  gold,  being  im- 
movable, it  is  impossible  to  keep  it  perfectly  clean,  as  the  metal 
will  gradually  tarnish  in  parts  out  of  reach  of  the  brush,  and 
will  gather  ofi:ensive  matter  on  its  surface  and  in  its  interstices. 

Fifth.  In  cases  where  it  becomes  necessary  to  temporarily 
remove  the  bridge  for  the  purpose  of  repair,  or  because  of  dis- 
ease in  the  teeth  which  support  it,  the  operation  is  diflicult  and 
the  bridge  is  usually  injured  so  as  to  unfit  it  for  re-insertion. 

Sixth.  The  teeth  which  support  the  bridge  are  required  to 
bear  more  force  and  pressure  than  nature  intended, — where  the 
piece  is  large  many  times  more, — and,  the  bridge  being  perma- 
nenth'  attached,  at  no  time  can  an}'  rest  be  given  the  abutments 
or  the  contiguous  parts  by  its  temporary  removal.     Thus  in  a 


136  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

piece  of  bridge-work  consisting  of  fourteen  teeth  supported  by 
four  natural  ones,  each  one  of  the  natural  teeth  may  have  to 
bear  more  than  three  times  the  strain  in  supporting,  and  the 
force  in  masticating,  that  was  intended.  The  ultimate  result  is 
evident  to  any  one  who  is  experienced  in  dental  practice;  and 
unless  the  anatomical  conditions  are  most  favorable,  the  useful- 
ness and  durability  of  such  work  is  decidedly  limited  in  character, 
considering  the  time,  trouble,  and  great  expense  attending  it. 

Such  are  the  objections  M-hich  have  been  put  forth  against 
bridge-work ;  and  yet,  whatever  may  be  urged  against  it,  its 
advantages  have  won  Irom  a  nuijority  of  the  profession,  includ- 
ing many  accepted  authorities,  an  enthusiastic,  almost  a  sen- 
sational, indorsement;  some  practitioners  even  going  so  far  as 
to  proclaim  it  the  only  true  method  for  the  insertion  of  artificial 
teeth. 

Judged  impartially,  bridge-work  has  many  advantages  when 
practiced  by  experts  who  properly  construct  and  apply  it. 
Without  doubt  it  has  been  abused.  Bridges  have  been  inserted 
where  the  support  was  insufficient,  or  the  construction  was  wrong 
in  principle  or  faulty  from  lack  of  skill.  More  than  this  :  bridge- 
work  has  been  passing  through  the  experimental  period,  when 
failures  are  apt  to  appear  more  prominently  than  successes. 
The  chronicles  of  dental  literature,  however,  in  this  respect  offer 
only  a  repetition  of  the  historical  difficulties  that  attend  all  new 
departures  in  the  arts. 


C  II A  P  T  E  H     I. 

CONSTRUCTION    OF   BRIDGE-WORK. 

To  the  skilled  mechanical  dentist,  well  versed  in  metal-  and 
crown-work,  bridge-work  does  not  present  extreme  difficulty. 
The  foundations  or  abutments — that  is,  the  teeth  or  roots  on 
which  the  bridge  will  rest — are  first  to  be  considered,  due  respect 
being  paid  to  the  mechanical  principles  controlling  the  leverage 
and  the  force  of  occlusion  in  mastication.  The  amount  of  strain 
that  can  be  borne  by  the  different  teeth,  individually  and  collect- 
ively, according  to  their  position  and  condition  of  health,  should 
be  carefully  calculated. 

As  a  rule,  the  force  exerted  upon  the  incisors  in  occlusion  will 
be  directed  outward  on  the  upper,  and  inward  on  the  lower 
teeth,  and  its  tendency  when  they  support  a  bridge  will  be  to 
gradually  push  them  out  of  line  in  each  direction.  When  the 
incisors  are  replaced  by  a  bridge,  the  tendency  of  the  force  of 
occlusion  is  toward  a  similar  result.  On  the  bicuspids  and 
molars  the  force  is  direct.  The  rules  which  govern  the  number 
and  position  of  the  teeth  or  roots  that  are  required  or  should  be 
used  as  foundations  for  bridges,  in  practice  are  as  follows  : 

One  central  root  will  support  two  centrals,  and  if  spurs  or 
l>ars  from  the  sides  of  the  bridge  rest  upon  or  are  anchored  in 
the  adjoining  teeth,  a  lateral  in  addition. 

Two  central  roots  will  support  the  four  incisors,  spurs  or  bars 
resting  on  or  anchored  in  the  cuspids  to  be  used  additionally,  if 
the  case  requires  them. 

The  cuspid  roots,  alone  oi*  with  the  aid  of  a  central  root,  will 
support  the  six  anterior  teeth. 

One  molar  or  bicuspid  on  one  side,  and  a  bicuspid  or  molar 
on  the  other,  with  one  or  two  roots  in  an  intermediate  position, 
will  support  a  bridge  between  them. 

One  right  and  one  left  molar,  with  the  assistance  of  the  two 
cuspids,  will  suppoi't  a  bridge  comprising  the  entire  arch. 

137 


138 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


A  bridge  on  one  side  of  the  mouth  can  be  supported  by  two 
or  three  teeth  or  roots  on  that  side.  The  cuspids  always  afford 
the  most  reliable  support. 

In  general,  the  application  of  these  principles  will  cover  the 
subject  of  foundations,  the  operator  being  governed  by  the  exact 
condition  of  individual  cases.  In  a  bridge  of  the  six  anterior 
teeth  on  the  two  cuspids,  when  the  articulation  of  the  antagon- 
izing teeth  is  close  and  deep,  the  strain  should  be  relieved  by  an 
additional  attachment  of  the  bridge  to  the  teeth  posterior  to  the 
cuspids. 

Fig.  278. 


The  preparation  of  teeth  or  roots  to  support  a  bridge  is  the 
same  as  for  ordinary  crowms,  except  that  the  trimming  of 
the  sides  and  the  drilling  of  the  root-canals  of  the  various 
anchorages  should  be,  as  far  as  possible,  in  parallel  lines,  so  that 
the  collars  and  posts  of  the  crowns  shall  move  readily  to  their 
places  in  the  adjustment  of  the  finished  l;)ridge. 

Teeth  or  roots  which  are  to  be  crowned  with  all-gold  cap 
crowns  are  crowned  by  some  one  of  the  methods  described. 
Those  on  which  porcelain  fronts  are  to  be  used  are  merely 
capped,  the  posts  being  soldered  and  allowed  to  project  a  short 
distance  below  the  caps. 

The  case  represented  in  Fig.  278  will  be  used  to  illustrate  the 
construction  of  a  piece  of  bridge-work  in  all  its   details.     The 


CONSTRUCTION  OF  BRIDGE-WORK. 


139 


abutments,  or  supports,  consist  of  the  right  second  molar  capped 
with  an  all-gold  crown,  constructed  in  sections  by  first  forming 
the  collar  and  then  soldering  on  the  cap  (see  page  89),  the  two 
cuspid  roots  capped  for  collar  crowns  with  porcelain  fronts  (see 
page  84),  and  the  left  first  molar,  which  will  aftbrd  anchorage 
to  a  bar  on  that  side  of  the  bridge  (Fig.  279).  A  slot,  dovetail 
in  form,  is  usually  cut  well  into  the  body,  but  not  to  an  extent 
that  will  endanger  the  pulp  of  the  last-named  crown  (Fig.  280). 
If  the  tooth  is  not  decayed,  it  can  be  first  opened  up  with  a 
rubl)er  and  corundum  disk.     The  shaping  of  the   slot  is  best 


Fig.  279. 


Fig.  280. 


accomplished  with  fissure-burs.  With  the  crowns  and  caps  in 
position,  an  impression  and  articulation  of  the  case  are  then 
taken  with  plaster  slightl}-  colored  with  carmine.  The  plaster 
is  mixed  moderately  thick  and,  with  the  aid  of  a  spoon,  placed 
around  in  the  mouth  on  the  crowns,  caps,  and  parts  to  be 
included  in  the  bridge,  and  the  antagonizing  teeth  occluded 
tightly  and  so  held  until  the  plaster  sets.  The  mouth  is  then 
opened  and  tlie  plaster  carefully  removed,  the  pieces  being 
adjusted  together  should  it  break.  The  crowns  and  caps  (the 
latter  held  more  firmly  by  the  protruding  ends  of  the  ]>ins)  are 
removed  in  it.  The  plaster  is  then  varnished,  and,  on  the  side 
containing  the  crowns,  a  model  is  run,  composed  of  e([ual  parts 
of  calcined  marble-dust  and  plaster,  to  which  is  added  a  little 


140 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


sulphate  of  potassium, — less  than  the  proportion  of  salt  generally 
used, — which  causes  the  mixture  to  set  hard  quickly.  AVhen  the 
model  has  set,  it  is  mounted  with  plaster  on  an  articulator,  and 
the  other  side  giving  the  articulation   made  at  the  same  time. 


Fig.  281. 


Fig.  282. 


51  M 


/) 


When  the  impression  plaster  is  removed  (an  operation  which  is 
greatly  facilitated  by  its  having  been  colored  with  carmine),  a 
correct  model  and  articulation  of  the  case  will  be  found,  with 
the  crowns  and  caps  in  exact  position  as  in  the  mouth  (Fig.  281). 

Another  method  is  to  iirst  take 
the  impression  in  an  impression- 
tray,  and  then  tlie  articulation  in 
wax,  and  make  a  model  and  ar- 
ticulation from  them  in  the  usual 
manner. 

The  pins  protruding  from  the 
caps  on  the  model  are  next  cut 
off.  Teeth  are  selected, — ordi- 
nary plate  teeth  for  the  incisoi's  and 
cuspids,  and  partial  teeth,  repre- 
senting the  front  section  of  the 
tooth  and  styled  porcelain  facings, 
which  were  specially  designed  for  crown-  and  bridge-work,  for 
the  bicuspids  and  molars  (Fig.  282).  Cuspids  are  sometimes 
used  to  form  the  fronts  for  bicuspids.  The  teeth  are  ground 
and  fitted  to  the    model    and   articulation,    so    that    the    labial 


\j 


V 


95 


-  iB*' ""ijii^i.-^ 


CONSTRUCTION  OF  BRIDGE-WORK. 


141 


upper  edge  of  the  teeth  shall  press  lightly  on  the  gum.  Those 
which  are  intended  to  form  the  fronts  of  the  caps  on  the  cuspid 
roots  should  be  adjusted  in  the  ordinary  manner  for  single 
crowns.  To  determine  the  proper  positions  of  the  teeth  for 
producing  the  best  appearance,  they  can  be  adjusted  in  the  mouth 
on  wax,  without  the  gold  crowns  or  caps  of  the  supports. 
The  correct  position  of  the  teeth  on  the  model  having  been 
obtained,  investing  material,  composed  of  one  part  plaster  to 
two  of  calcined  marble-dust,  is  placed  on  the  outside  of  the 
model   on  the  labial    aspect  of  the  teeth,  merely  sufficient  in 

Fig.  288. 
C  A 


A  iinil  B.  central  incisor  and  bicuspid  ready  for  metallic  l^ackinpr.    C.  is  a  central  backed. 
D,  D,  D,  porcelain  fronts  as  they  appear  on  insertion  after  the  process  of  Ijacking,  capping,  and 


soldering. 

quantity  to  hold  them  in  position,  thus 
The  wax  is  then  removed,  exposing  the 
permitting  their  form  and  position  to  be 
The  porcelain  teeth  and  fronts,  with  the 
for  the  roots  capped,  are  then  removed 
ment,  and  the  base  ground  from  a  line 
below  the  pins,  straight  to  the  labio-cervical 
"2f-!3).     This   is  to  form   the    self-cleansins2: 


forming   a   matrix, 
palatal  portion,  and 
studied  (Fig.  283). 
exception  of  fronts 
from    their   invest- 
on  the  palatal  side 
edge  (A  and  B,Fig. 
spaces,  if  they   are 


142 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


desired.  The  incisors  are  then  backed,  using  either  very  thin 
platinum  or  pure  gold  (C).  The  backings  are  allowed  to  extend 
just  over  the  incisive  edge  as  a  protection  to  it,  and,  if  preferred, 
down  on  the  curve  of  the  self-cleansing  space.  A  more  desirable 
result  is  secured  if  the  backing  extends  only  to  the  edge  of  the 
self-cleansing  space,  and  the  porcelain  is  polished,  as  its  surface  is 
superior  in  cleanliness  to  that  of  gold. 

The  bicuspid  and  molar  porcelain  fronts,  their  tips  being 
ground  off  (A,  Fig.  284),  are  lined  in  the  same  manner.  A  cap 
of  pure  gold  or  gold  lined  with  platinum,  representing  the 
grinding-surface  of  each  tooth,  is  struck  up  as  described  and 


Fig.  284. 


Fig.  285. 


Iplp-B 


jjMiS 


illustrated  in  ihe  construction  of  gold  crowns  (see  page  92),  and 
the  concave  portion  filled  by  melting  in  scraps  of  20-carat  gold 
plate.  The  surface  is  then  ground  smooth  (B),  and  closely  fitted 
to  the  tip  of  the  porcelain  front  to  form  the  occluding  surface 
in  accordance  with  the  articulation  of  the  lower  teeth,  and  the 
space  filled  in  with  wax.  This  metallic  occluding  surface  is  to 
protect  the  porcelain.  Triangular  pieces  of  gold  plate  or  plat- 
inum foil  (C)  arc  then  cut  and  fitted  to  the  sides,  over  which 
they  should  extend  slightly,  and  the  tooth  is  invested,  leaving 
the  back  open,  presenting  the  form  of  a  pocket  (Fig.  285). 

The  bar  intended  to  be  anchored  in  the  slot  cut 
in  the  molar  on  the  left  side,  which  is  made  of  iridio- 
platinum  wire,  about  No.  15  standard  gauge,  with 
the  end  shaped  as  shown  in  Fig.  286,  is  fastened 
with  wax  to  the  tooth  and  cap,  and  adjusted  in  the 
mouth  to  obtain  accuracy  of  position  before  soldering. 

All  the  teeth  should  be  invested  at  the  same  time,  the  inci- 
sors and  porcelain  fronts  to  the  cuspid  crowns  as  shown  in  Fig. 
287.     In  the  soldering,  20-carat  gold  plate  should  be  melted  into 


Fig.  286. 


CON.STRUCTIOX  OF  BRIDGE-WORK. 


143 


the  pockets  formed  bv  the  cap  and  side  pieces  to  fill  out  to  the 
line  at  A,  Fig.  288,  and  flowed  over  the  backings  of  the 
incisors  and  cuspid  fronts  in  sufficient  quantity  to  shape  them  as 
shown  at  B,  Fig.  289.  The  teeth  forming  tlu'  bridge  between 
the  crowns  are  called  "dummies."      After  tbe  solderine-  and 


Fio    L'ST. 


removal  of  the  borax  with  acid,  eaeh  tooth  is  then,  when  it  is 
easily  done,  very  carefully  trimme  1  and  finislied. 

The  teeth  are  next  placed  in  their  relative  positions  on  the 
model  and  attached  with  wax,  as  shown  at  D,  D,  D,  Fig.  283. 
The  model  is  then  detached  from  the  articulator,  trimmed  down 


Fig.  289. 


Fig.  290. 


as  much  as  i)Ossible  in  size,  and  additional  investing  material, 
composed  of  two  parts  marble-dust  and  one  of  plaster,  applied 
until  alljof  the  bridge  is  covered  except  the  space  along  the 
backings  andjcrowns  where  they  are  to  be  united  in  the  solder- 
ing (Fig.  290).     In  the  spaces  between  the  backings  pieces  of 


144 


ARTIFICIAL  CROWN-  AND  BRIDGE- WORK. 


gold  or  platinum  plate  or  wire,  about  one-eighth  of  an  inch  long, 
are  placed  lengthwise,  and  the  joints  are  then  well  soldered  with 
20-carat  gold  solder.  The  soldering  is  hest  done  on  a  concave- 
shaped  piece  of  charcoal  with  a  gas  blow-pipe.  When  the 
bridge  is  removed  for  finishing,  the  joints  of  the  backings  and 
crowns  are  finished  with  corundum-wheels  and  points  and  moose- 
hide  points  on  the  engine,  and  the  entire  bridge  finely  polished 
with  whiting  carried  by  a  brush-wheel  on  the  lathe.  Any  little 
pits  that  may  exist  can  be  filled  in  with  gold  foil.     The  bridge  is 

then  ready  for  insertion    (Fig. 
^'«-  2^^-  291).    If  the  constructive  details 

have  been  properly  performed 
as  described,  a  finished  piece 
of  lu'idge-work  is  the  result. 

In  constructing  bridge-work 
many  prefer,  after  the  porcelain 
fronts  are  backed  and  the  caps 
forming  the  occluding  surfaces 
of  the  bicuspids  and  molars  arc 
properly  adjusted  on  the  model, 
to  invest  and  do  the  entire  sol- 
dering at  once.  When  this  plan 
is  followed,  pieces  of  gold  wire  should  be  laid  lengthwise  in  the 
slots  under  the  gold  cap  of  the  porcelain  fronts,  and  the  parts 
filled  in  and  all  the  sections  of  the  bridge  joined  together  in 
the  soldering.  By  this  method  there  is  less  liability  of  fracturing 
the  porcelain  fronts,  but  the  finishing  of  the  bridge  is  not  so 
easily  or  so  perfectly  done. 

In  large  pieces  of  work  there  is  some  liability  to  warping, 
which  may  be  avoided,  whichever  method  of  soldering  is 
adopted,  by  first  removing,  in  proper  position,  the  "dummies" 
and  soldering  those  of  each  span  together.  The  spans  are  then 
replaced  in  the  matrix  and  soldered  to  the  abutments. 

Adjustment  and  Attachment. — The  bridge  when  finished  is  ad- 
justed in  the  mouth,  every  point  carefully  examined,  and  any 
alterations  required  are  then  made.  Should  the  edges  of  the 
collars  of  any  of  the  crowns  catch,  so  as  to  prevent  their  being 
placed  in  position,  a  small  quantity  of  articulating  paste  should 


CONSTRUCTION  OF  BRIDGE- WORK. 


145 


be  applied  and  the  point  found  and  trimmed  off.  If  extensive 
warping  has  occurred  in  the  soldering,  the  bridge  must  be  sawed 
apart  in  one  or  two  places,  adjusted  in  the  mouth,  and  removed 
in  an  impression-tray,  using  sufiicient  investing  material  (equal 


Fig.  292. 


parts  of  plaster  and  marble-dust  with  the  usual  quantity  of  sul- 
phate of  potassium)  to  cover  only  the  points  of  the  teeth  and 
crowns  (Fig.  292).  The  inner  surface  of  the  tray  should  be 
oiled. 

The  bridge  and  the  investinc;  material  are  then  removed 
together  from  the  impression-tray,  and  more  investing  material 
is  added  to  complete  the  investment.  The  cut  parts  of  the 
bridge  are  then  soldered  together. 

When  the  adjustment  of  Fig.  293. 

the  bridge  is  accomplished, 
it  can  at  first  be  tempora- 
rily attached  with  gutta- 
percha if  desired.  For  its 
permanent  attachment  the 
pins  or  posts  of  the  crowns 
are  barbed,  and  the  teeth 
and  roots  to  which  crowns 
have  been  fitted  are  then 
treated  the  same  as  single 
crowns,  and  the  bridge  cemented  on  with  a  slow-setting  oxyphos- 
phate  cement  (see  page  128).     The  end  of  the  bar  is  anchored  in 

10 


146  ARTIFICIAL  CB.OWN-  AND  BRIDGE-WORK. 

the  slot  by  either  a  gold  or  an  amalgam  filling.     Fig.  293  repre- 
sents the  bridge  in  position. 

Fig.  294. 


Fig.  295. 


Fig.  296. 


/    ; 


Fig.  297. 


CONSTRUCTION  OF  BRIDGE-WORK. 


147 


The  Consfrifcfi'oit  of  Small  Pieces  of  Bn<l(i<'-irork\&  much  simplilied 
by  the  following  method  :  Crowns  are  first  made  for  the  teeth  or 
roots  that  form  the  abutments  and  temporarily  placed  in  position. 
The  teeth — "  dummies  " — which  form  the  span  having  been 
ground  and  backed,  are  adjusted  and  cemented  with  resin  and 
wax  in  proper  position  between  the  crowns.  The  crowns  and 
dunmiies  are  then  removed  together,  in  an  impression-tray  filled 
with  investing  material.     The  inside  of  the  tray  should  be  coated 

Fig.  298. 


with  a  film  of  wax  with  the  surface  serrated.  The  impression- 
tra}^  is  then  heated,  and  the  investment  with  the  crowns  and 
dummies  removed;  more  investing  material  is  then  mixed,  and 
the  exposed  parts  of  the  crowns  and  teeth  covered.  The  invest- 
ment, when  set,  is  then  cut  away  sufiiciently  to  expose  the  parts 
that  are  to  be  filled  in  and  united  together  in  the  process  of 
soldering.  Figs.  29-1:,  295,  296,  297,  298  represent  cases  of  Itridge- 
work  constructed  in  this  manner. 


CHAPTER    II. 

SPECIAL  PROCESSES  AND  APPLIANCES  IN  BPvIDGE-WORK 

Shoulders  on  the  Anterior  Teeth  are  sometimes  desirable,  especi- 
ally on  the  superior  cuspids  at  the  point  of  occlusion  with  the 
lower  teeth.  A  shoulder  can  be  made  l)y  melting  gold  plate 
into  the  form  of  a  small  ball  or  globule,  then  flattening  it  out 
and  soldering  it  against  the  backing. 

Another  method  is  to  attach  with 
Fig.  299.  Fig.  300.      ^^^  transversely  across  the  backing 

/Av  in  proper  position  a  strip  of  gold 
plate  as  shown  in  Fig.  299,  and  then 
flow  in  gold  to  the  line  A,  by  spe- 
cially investing  or  in  the  soldering  of 
the  bridge. 

Solid  Gold.  Croir/is. — In  a  close  articulation,  when  the  patient 
prefers  strength  to  appearance,  the  bicuspids  and  molars  should 
be  made  of  solid  gold.  They  are  constructed  by  stamping  up 
the  cap  (A,  Fig.  300)  representing  the  grinding-snrface  (see 
page  90),  and  then  adjusting  and  cementing  with  wax  a  piece 
of  plate  cut  and  shaped  to  form  the  front  and  sides  (B),  which 
is  then  invested  and  filled  in  witli  gold  solder,  or,  if  pure  gold  has 
been  used  in  the  sections  of  the  crown,  with  18-  or  20-carat  plate. 
Seamless  contour  crowns  can  be  used  for  the  purpose  as 
follows :  The  proper  crowns  having  been  selected,  the  gold  is 
trimmed  and  the  crowns  adjusted  in  position  on  the  model.  A 
matrix  of  plaster  is  then  placed  on  the  labial  side,  which  permits 
the  palatal  portion  to  be  studied,  the  crown  removed,  and  cut 
away  to  the  form  required.  They  are  then  removed,  invested, 
and  filled  in  with  gold  plate. 

A  bar-bridge  can  be  made  with  these  by  passing  an  iridio-pla- 
tinum  wire  through  the  crowns  l)efore  filling  in  (Fig.  301). 
148 


SPECIAL  PROCESSES  AND  APPLIANCES  IN  BRIDGE-WORK     149 


A  Solid  Gold  Croini  for  a  Fulpkss  Molar ^  supporting  the  uiid 
of  a  l)ar  as  shown  in  Fig.  302,  is  constructed  as  fohows :  The 
natural  crown  is  ground  down,  banded,  capped,  and  pivoted  as 
in  Fig.  303.  The  gohl  forming  the  top  of  the  cap  is  made  per- 
fectly flat  and  left  projecting  a  little  at  the  sides.     A  contoured 


Fig.  301. 


Fig.  302. 


Fig.  303. 


crown  of  pure  gold,  or  gold  lined  with  platinum 

as  a  precaution  against  melting,  is  shortened  suf- 

flciently  to  represent  the  absent  coronal  section 

of  the  tooth,  and  with  a  corundum-disk  the  orifice  ""'      v-' 

of  the  anchorage  cavity  is  formed.     A  shell  of  thin  platinum  of 

the  size  and  shape  of  the  anchorage  cavity  is  then  inserted  and 

cemented  with  wax  on  the  inside  of  the  crown.     The  crown  is 

then  invested  and  filled  with  18-carat  gold  solder,  which  should 

bo    cut   into  small    pieces,   and  be   placed    successively  in    the 

Fig.  304. 


crown  and  melted  by  maintaining  a  uniform  heat  with  the 
large  flame  of  a  blow-pipe.  The  base  of  the  crown  is  next 
ground  level  and  accurately  fitted  to  the  cap  and  articulated  to 
the  antagonizing  teeth.  It  is  then  clamped  in  position  on  the 
cap,  the  pivots  of  which  are  protected  with  investing  material 
(Fig.  304),  and  soldered  to  the  cap,  making  a  perfect  joint.  This 
is  an  easy  method  for  constructing  a  difficult  form  of  crown. 


150 


ARTIFICIAL  CROWN-  AND  BRIDOE-WORK. 


Fig.  305  illustrates  a  bridge  su[)ported  by  a  bar-anchorage  in  a 
solid  gold  crown  on  the  roots  of  a  molar  and  a  shell  crown  on 
a  cuspid. 

Connecting  Bands  or  Bars  for  Bii<l<jes,  which  obviate  the  removal 
of  crowns  of  intervening  natural  teeth  between  the  sections  of  a 
projected  bridge,  are  formed  by  passing  a  heavy  band  of  oval- 


FiG.  305. 


Fig.  306. 


Fig.  307. 


Fig.  308. 


shaped  gold  or  iridio-platinum  wire  anjund  the  intervening 
teeth,  close  to  but  not  touching  them,  and  resting  lightly  on  the 
gums.  The  application  of  this  device  was  first  illustrated  by 
br.  J.  L.  Williams,  Figs.  306,  307,  and  308. 

Intervening  roots  between  the  abutments  of  a  projected  bridge 
should  not  be  extracted,  but  treated,  filled,  and  trimmed  level 
with  the  gum,  as  the}'  can  be  made  to  afford  some  support  for 


SPECIAL  PROCESSES  AND  APPLIANCES  IN  BRIDGE-WORK.     151 


the  bridge,  which  may  rest  upon  them.  Figs.  309  and  310  rep- 
resent a  case  in  which  the  root  of  the  cus[»id  on  the  right  side 
has  been  so  treated  and  utilized. 


Fig.  300. 


Fig.  310. 


Shell  Aiirhnra;/e  <>r  f'roirn. — The  construction  of  a  shell  anchor- 
age for  a  cuspid  and  its  practical  application  in  supporting  a 


152 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


bridge  cannot  be  better  described  tban  in  the  following  words  of 
Dr.  J.  L.  Williams : 

"Fig.  oil  sbows  a  piece  of  work  made  for  a  case  of  quite 
frequent  occurrence.  It  represents  tbe  restoration  of  the  inferior 
bicuspids  and  first  molar  of  the  right  side.  A  gold  crown  is 
made  for  the  second  molar,  and  the  three  intervening  teeth  or 
*  dummies  '  are  then  constructed.  For  the  support  of  the  ante- 
rior end  of  the  bridge,  the  method  hitherto  practiced  has  been 

Fig.  311. 


to  excise  the  crown  of  the  cuspid  and  fit  a  porcelain  crown  with 
gold  backing  to  the  root,  and  to  this  the  anterior  end  of  the 
bridge  is  soldered. 

"  Fig.  312  illustrates  a  device  which  obviates  the  necessity 
for  removing  the  cuspid  crown.  A  gold  l)and  is  fitted  around 
the  cuspid  at  the  front,  shown  at  a.  This  l)and  is  allowed  to 
pass  a  little  beneath  the  margin  of  the  gum,  so  as  to  make 
the  smallest  possible  exhibition  of  gold.     On  the  lingual  aspect 

Fig.  312. 


of  the  tooth  the  band  is  allowed  to  be  nearly  the  length  of  the 
crown.  It  will  be  seen  that  when  this  l)an(l  is  fitted  as  perfectly 
as  possible  there  must  necessaril}^  be  quite  a  vacancy  betAveen 
the  upper  part  of  the  lingual  surface  of  the  tooth  and  the  band. 
It  is  important  that  this  portion  of  the  band  fits  the  tooth 
perfectly,  and  an  accurate  adaptation  is  obtained  as  follows : 
A  piece  of  very  thin  platinum  or  pure  gold,  rolled  to  N"o.  35 
American  gauge,  is  fitted  over  that  portion  of  the  lingual  surfoce 


SPECIAL  PROCESSES  AND  APPLIANCES  IN  BRIDGE-WORK.    153 

of  tlie  tooth  which  it  is  to  cover,  d,  Fig.  312,  shows  the  shape 
that  this  little  plate  usually  assumes.  "  It  can  be  perfectly  fitted  by 
the  use  of  a  burnisher,  and  then,  with  the  band  in  position,  a  drop 
of  melted  resin  wax  is  flowed  into  the  vacant  space  between  the 
pure  gold  and  the  band.  It  is  now  removed  from  the  tootli,  in- 
vested, and  after  melting  out  the  wax  solder  is  flowed  into  the 


Fig.  31? 


Fig.  814. 


f} 


vacancy,  tilling  completely  the  space  occupied  by  the  wax.  The 
top  of  the  lingual  portion  will  now  be  thicker  than  is  necessary, 
but  it  can  be  ground  or  filed  down  to  the  proper  thickness.  '  We 
now  have  a  band  which  fits  all  portions  of  the  tooth  perfectly. 
The  anterior  end  of  the  bridge  is  soldered  to  this  band,  and  after 
the  work  is  properly  finished  it  is  cemented  in  phu-e  in  the  usual 


Fig.  315. 


Fig.  316. 


manner.      I>  and  <•,  Fig.   312,  show  side  and  lingual  views  of 
ihis  band  after  the  fitting  is  completed."' 

A  Scdinh'ss  S/'c/l  Anr/uirni/t  is  formed  as  follows:  From  an 
impression  of  a  natural  crown  taken  in  plaster,  gutta-percha,  or 
moldine.  a  die  in  fusible  metal  is  formed,  and  from  it  a  counter- 
die  in  lead  is  made.     (See  "  Gold  Seamless  Cap  Crown.")     On 


154  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

the  die  a  crown  is  stamped  from  a  seamletsri  cap  of  p^old  (Fig.  313). 
This  crown  is  then  fitted  on  the  natural  tooth,  the  labial  aspect 
of  which  is  exposed  by  the  removal  of  the  section  of  gold  cover- 
ing it  (Figs.  314  and  315).  A  shell  for  a  cuspid  can  be  made 
from  a  gold  collar  as  well  as  a  cap.  The  shell  formed  in  either 
manner  is  then  filled  with  investing  material,  and  strengthened 
by  flowing  20-carat  solder  over  the  surface. 

This  process  for  cuspids  has  decided  advantages  for  the  easy 
formation  of  a  perfect-fitting  crown  or  shell  for  bridge-work. 

A  shell  crown  can  be  additionally  secured  by  a  pin  soldered, 
or  a  gold  filling  introduced,  when  the  gold  is  removed  at  the 
labio-cervical  part,  as  shown  at  A,  Fig.  315. 

Fig.  316  illustrates  a  case  of  the  lower  incisors  supported  by 
shell  crowns  on  the  cuspids. 


CHAPTER    III. 


EXTENSION   BRIDGES. 

This  term  is  applied  to  bridges  which  are  chiefly  supported 
bv  one  abutment.  In  rekition  to  the  anterior  teeth,  it  consists 
in  attaching  a  dummy  to  an  artificial  crown,  to  replace  an 
adjoining  absent  tooth.  A  bridge  of  this  style  replacing  two  or 
three  of  the  posterior  teeth  is  formed  by  using  two  of  the  teeth 


Fig.  317 


Fig.  318. 


Fig.  8-i(). 


anterior  to  it  as  one  abutment,  and  a  saddle  for  the  other.  A 
saddle  is  an  oval-shaped  piece  of  gold,  of  the  form  of  the  gum 
and  a  little  larger  than  the  base  of  the  tooth,  ^ilaced  under  the 
posteriqi"  tooth  of  the  bridge. 

Figs.  317  and  318  represent  an  extension  bridge.  A  crown 
on  the  cuspid,  an  all-gold  crown  on  the  bicuspid,  and  a  saddle, 
are  the  abutments.  In  constructing  this  bridge,  tlie  teeth  foi-m- 
ing  the  abutments  were  first  crowned.  The  crowns  were  then 
adjusted  in  position,  and  au  impression  and  ai"ticuh\tion  taken  in 

165 


156 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


plaster,  in  which  the  crowns  were  removed.  From  this  impres- 
sion a  model  was  made  of  plaster  and  marble-dust,  and  an 
articulation  in  plain  plaster.     On  the  model,  with  the  crowns  in 


Fig.  321. 


Tig.  322. 


position  as  in  the  mouth,  the  bridge  was  then  constructed  by  the 
methods  described  on    page  141.     The    part  of  the  model  on 


Fig.  323. 


Fig.  324. 


which  the  saddle  rested  was  marked,  and  enough  of  the  surface 
of  the   plaster  removed  to  cause   the  saddle   to   press   tightly 

Ftg.  325.  Fig.  326. 


against  the  soft  tissues  when  the  bridge  should  be  completed  and 
inserted  in  the  mouth. 

A  .shell  crown  on  a  cuspid  can  be  used  as  an  abutment  in  this 


EXTEXSluy  BRIDGES. 


157 


style  of  bridge,  instead  of  excising  the  natural  crown  and  mount- 
ing an  artificial  crown  on  the  root  for  the  ^/urpose  (Figs.  319, 
320). 


Fig.  327. 


Fig.  828. 


Figs.  321,  322,  323,  and  324  represent  small  extension  l)ri(lges 
of  frequent  construction,  and  Fig.  325  a  pin-shell  crown  which 
can  he  made  to  support  a  porcelain  front  representing  a  cuspid 
or  hicuspid. 

Fig.  330. 


Figs.  326,  327,  and  328  represent  an  extension  hriduv  c-on- 
structed  hy  Dr.  H.  A.  Parr,  of  Xew  York.  The  anterior  ahut- 
ment  consists  of  the  six  front  teeth,  which  have  all  been  crowned 


Fig.  331. 


Fig.  332. 


and  Joined  together,  the  pul}is  being  preserved  in  the  incisors 
A  saddle  on  each  side  forms  the  posterior  abutments. 


158  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

A  Spur  S"j)pnrf  consists  of  a  flange  formed  at  the  end  of  an 
extension  bridge,  aflbrding  support  by  resting  on  the  pahital 
wall  of  either  an  incisor  or  cuspid,  or  in  the  sulcus  Ijetween  the 
cusps  of  a  bicuspid  or  molar.  Fig.  329  illustrates  a  case  with  a 
spur  resting  against  a  cuspid.  In  the  case  represented  in  Figs. 
330  and  831  the  spur  rests  in  an  indentation  in  an  amalgam  fill- 
ing in  the  molar,  and  is  termed  a  cantilever  bridge.  A  bridge 
formed  with  a  spur  which  is  anchored  in  a  filling  is  practically 
a  one-bar  bridge  (Fig.  332). 


CHAPTER    IV. 

DOUBLE    BAR-BPvIDGES. 

In  this  style  of  bridge  the  teeth  or  (huiimies  tbrmiiio-  it  are 
siip[)()rte(l  l)y  bars  anchored  l)y  fillings  in  tlie  natural  teeth  form- 
ing the  alnitnients.  Its  use  is  eontined  to  the  insertion  of  one  or 
two  teeth.  In  the  ineisors  and  cuspids  the  cavities  of  anchorage 
are  formed. in  the  palato-a})[»roximal  portion  of  the  teeth  con- 
tiguous to  the  space  to  be  bridged,  aV)out  one-third  of  an  inch 
from  the  gingival  margin  (Fig.  333),  and  having  direct  access 
iiito  at  least  one  of  the  cavities  through  the  ai)proximal  wall. 

In  constructing  the  bridge  the  l)ar 
is  first  made.  Iridio-platinum  wire 
al)0ut  N(^.  14  to  Xo.  16  U.  S.  standard 
gauge  is  preferal)ly  used  for  the  pur- 
pose. The  extremities  are  formed 
square  or  triangular,  increasing  in  size 
towards  each  end,  and  fitted  dee})  into 
the  cavities  of  the  teeth  which  are  to 
support  them.  The  bar  is  then  adjusted 
and  a  suitable  plate  tooth  ground  and 
fitted  in  [)roper  position  against  it. — a 

portion  of  the  labial  surface  of  the  bar  beiuu-  renu)ved  to  receive  it. 
The  tooth  is  tlien  backed  with  \erv  tliin  platimini,  cemented  with 
wax  to  the  bar,  and  the  tooth  and  bar  removed,  invested,  and  sol- 
dered. Sufiicient  gold  sbonld  be  added  to  properlv  contour  the 
l>art(A,  Fig.  333).  Gold  and  amalgam  are  the  only  suitable  fillings 
for  anchoring  the  ends  of  the  bar.  Amalgam  is  o])jectiouable  onlv 
when  the  position  of  the  cavity  renders  it  visible.  It  can,  how- 
ex'er.  when  set  be  partially  i'enio\-ed  at  tlie  exjiosed  ]iortion  and 
covered  with  gold.  Fastening  one  end  of  the  bar  tem}H)rarilv 
with  (^xyphosphate  while  the  other  is  being  sei-ured.  will  some- 

159 


160 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


times  facilitate  the  operation  of  anchoring.  When  gold  is  the 
filling-material  used,  the  rubber-dam  is  first  adjusted  on  the 
natural  teeth  and  the  bridge  placed  in  position  over  it. 

The  practical  success  of  this  style  of  bridge-work  depends 
chiefiy  upon  the  character  of  its  supports  and  the  skillfulness 
with  which  it  is  anchored. 

A  Bar-Bridge  loith  a  Detachable  Porcelain  Front  affords  access 
to  the  cavities  of  anchorage  and  admits  of  replacement  of  the 
porcelain  in  case  of  fracture. 

A  modification  of  Dr.  I.  F.  Wardwell's  method,  which  is 
simple  in  construction  and  application  in  comparison  with  most' 
forms  in  use,  is  as  follows :     A  thick,  narrow  piece  of  18-carat 


Fig.  334.       Fig.  335. 


Fig.  336. 


Fig.  337. 


gold  plate,  at  least  No.  18  standard  gauge,  is  soldered  to  the 
tooth  and  its  two  sides  undercut  with  a  very  thin  separating  file 
(Figs.  334,  335).  A  very  thin  piece  of  platinum,  covering 
the  whole  l)ack  of  the  tooth,  is  then  burnished  against  it,  well 
into  the  undercut  sides,  annealing  the  platinum  several  times 
during  the  operation.  The  platinum  is  then  held  in  a  flame 
wlnle  a  small  quantity  of  pure  gold  is  flowed  over  the  outer 
surface  and  tlien  refitted  to  the  l)ack  of  the  tooth,  to  which  it  is 
again  burnished.  This  operation  is  repeated  until  the  platinum 
and  gold  form  a  moderately  light  backing  which  fits  perfectly. 
The  platinum  surface  is  then  covered  with  investing  material,  and 
on  the  other  side  18-  or  20-carat  gold  plate  fiowed  until  a  suitable 
thickness  is  obtained.  When  trimmed  into  proper  shape  and 
attached  to  the  bar,  this  forms  a  substantial  ]>acking  or  socket 
(Fig.  336)  in  which,  when  the  bar  is  anchored,  the  porcelain  tooth 
can  be  fastened  with  a  little  oxyphos})hate  cement  or  gutta- 
percha (Fig.  337). 

The  Low  porcelain  front  consists  of  a  metallic  socket  into 


DOUBLE  BAR-BRIDGES. 


161 


wliicli  the  porcelain  facing-  fits,  being  retained  by  grooves  on 
the  sides.  The  metallic  part  is  soldered  in  position  and  the 
porcelain  front  then  cemented  on.     (See  page  119.) 

Fig.  338  represents  a  double'  bar-l)ridge  fornie'd  witb  an  all- 
gold  molar  crown. 

Dr.  J.  G.  Morey's  method  of  constructing  a  double  bar-bridge 
with  a  remova])le  molar  or  dummy  is  as  follows : 

The  bar  is  formed  as  seen  in  Fig.  339.  A  countersunk  molar 
is  ground  and  shaped  as  seen  [it  A  and  B,  Fig.  340.  To  the  base 
of  the  molar  and  up  in  tlu'  slot  is  shaped  and  fitted  the  shell  C, 


Fio.  388. 


Fig.  340. 


Fig.  339. 


Fio.  341. 


/RR"^^ 


made  of  a  \'erv  thin  })iece  of  gold  and  })latiuum  ^towu  metal  by 
first  stamping  it  on  a  fusible  metal  die  of  the  base  and  tben 
adapting  it  to  the  part.  A  thin  piece  of  clasp-metal  (D)  is  then 
formed  to  fit  over  the  liar  and  in  proper  position  into  the  slot  of 
tliesliell  (0,  Fig.  339),  to  which  it  is  soldered  by  investing  and 
soldering  on  the  inside  of  the  shell.  The  shell  is  then  cemented 
witli  oxyphosphate  on  to  the  base  of  tlie  molar  as  seen  at  A 
and  B,  Fig.  339,  and  is  secured  to  the  bar  l)y  springing  together 
the  edges  of  the  metal  at  C.  Fig.  341  illustrates  the  tooth  in 
])t)sition. 

11 


CHAPTER    V. 

EXTENSIVE  APPLICATIONS  OF  CROAYN-  AND  BEIDGE-WORK. 

The  following  illustrations  of  l)ri(lu'e-work  by  Dr.  H.  A.  Parr, 
of  JSTew  York,  show  to  what  an  extent  the  system  can  he  applied. 

EiG.  342. 


Pigs.  342,  343,  344,  and  345  represent  a  case  in  which  the 

Fig.  343. 


roots  of  the  two  superior  centrals,  a  partially  decayed  right  first 
molar,  and  a  badly  decayed,  }inl})less  kdt  first  molar  were  all  that 
162 


APPLICATIONS  OF  CROWN-  AND  BRIDGE-WORK. 


163 


remained  of  the  upper  natural  teetli.     On  the  two  central  roots 
were  mounted  collar  crowns,   and   on   tlie  two  molars  all-o-old 

Fig.  344. 


Fig.  345. 


Fig.  346. 


caji  crowns.     These   four   crowns  actinu"  as  al>utnient<   for  the 
hridgc   denture,  hore   1)etweeu   them,   proportionately  on    t'ach 


164 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


side,  the  force  and  leverage  of  occlusion.'    The  contour  of  the 
arch    in    the   region  of  the    cuspids  was   restored  by  a   skillful 

Ftg.  347. 


and  artistic  ])lacing  of  the  artificial  teeth,  which  are  prominent 
and  lono-. 


APPLICATIONS  OF  CROWN-  AND  BRIDGE- WORK.  165 

Fig.  350. 


M  \    1 


Fig.  351. 


Fig.  352. 


166 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


Figs.  346,  847,  348,  and  349  represent  a  ease  in  whcih  two 
large  and  firm  superior  cuspid  roots,  a  right  pulpless  molar  with 
a  saddle — an  invention  of  Dr.  Parr's — on  the  left  side  support  a 
large  bridge. 

Fig.  353. 


In  the  bridge-work  illustrated  in  Figs.  350,  351,  and  352  the 
crown  of  a  second  l)icuspid,  a  pulpless  molar,  and  the  roots  of  a 
cuspid  and  lateral  constitute  the  abutments. 


Fig.  354. 


The  following  Figs.  353  and  354  illustrate  an  extensive  case 
of  artificial  replacement  by  crowning  and  bridging  operations. 
Fig.  353  re])resents  the  case  as  presented  for  treatment.     The 


APPLICATIONS  OF  CROWX-  AND  BRIDGE- WORK.  167 

Fig.  355. 


Fig.  356. 


168 


ARTIFICIAL  CROWN.  AND  BRIDGE-WORK. 


few  remaining  superior  and  inferior  natural  teeth  had  no  corre- 
sponding antagonists,  which  caused  the  interlocking  and  abnor- 
mal condition  in  regard  to  occlusion  shown.  The  superior 
right  bicuspid,  the  left  central,  and  the  left  cuspid  were  crowned, 


Fig.  357. 


the  bicuspid  being  shortened  and  the  cuspid  lengthened  in  the 
operation.  The  intervening  lateral  root  between  the  central 
and  cuspid,  ha\'ing  been  treated  and  filled,  was  allowed  to 
remain.     With   the   three    crowns   to    serve   as  abutments  the 


Fig.  358. 


intervening  spaces  were  bridged  witli  artificial  teeth,  the  exten- 
sion on  the  left  side  being  supported  by  a  saddle.  The  spaces 
between  tlic  inferior  cuspids  and  molars  on  l)oth  sides  were 
bridged,  the  bicuspid  on  the  left  supporting  the  bridge,  instead 


APPLICATIONS  OF  CROWN-  AND  BRIDGE-WORK.  169 

of  the  cuspid,  us  on  the  right ;  the  k'ft  cuspid  was  crowned  and 
the  incisive  edges  of  the  incisors  trimmed  even. 

Fig.  354  ilhistrates  the  case  tinislied  and  shows  the  complete 
artificial  restoration  of  the  parts. 

•Figs.  355  and  356  represent  a  case  in  which  crown-  andltridge- 
work  has  been  extensively  applied.  The  occluding  surtaces  of 
the  teeth  were  affected  with  abrasion.  Gold  crowns  with  porce- 
lain fronts  were  mounted  on  the  incisors  and  cuspids,  the  pulps 
of  which  Ave  re  preserved.  The  posterior  teeth  were  crowned 
with  all-gold  crowns.  The  missing  teeth,  except  those  on  the 
inferior  left  side,  were  artificially  restored  with  bridge-work. 

In  the  case  illustrated  by  Figs.  357  and  358,  two  superior  mo- 
lars and  a  second  bicuspid  on  the  riglit,  and  a  first  bicuspid  and 
a  saddle  under  the  "  dummy  "  representing  the  first  molar  on 
the  left  side,  form  the  ainitments.  This  piece,  at  the  time  of 
writing,  had  been  worn  satisfactorily  for  four  years.  Prior  to 
the  insertion  of  the  bridge-work,  the  patient  had  worn  artificial 
teeth  on  a  jilate. 


Fig.  359. 


CHAPTER    VI. 

KEPAIR  OP  CROWN-    OR  BRIDGE-WORK. 

The  fracture  of  a  porcelain  front  to  a  permanently  attached 
bridge  is  an  annoying  accident  for  both  patient  and  dentist.  It 
is  usually  attributable  to  failure  to  properly  protect  the  incisive 
edge  or  occluding  surface  of  the  porcelain  with  metal,  a  precaution 
rendered  necessary  by  the  rigid  character  of  the  resistance 
offered  the  antagonizing  teeth  through  the  aljutments.  In  most 
cases  the  porcelain  can  be  replaced  without  the  removal  of  the 
bridge,  but  the  attachment  is  not  usually  so  reliable  as  in  the 

original  piece.  The  following  is 
the  method  usually  adopted  :  The 
surface  of  the  backing  to  the  por- 
celain is  trimmed  level,  the  plati- 
num pins  drilled  out,  and  the  holes 
slightly  countersunk  on  the  palatal 
side.  A  tooth  similar  to  the  one 
fractured,  with  long  pins,  is  ground 
and  fitted  to  the  backing.  The 
pins  are  then  riveted  on  the  palatal 
side,  into  the  countersunk  holes  of 
the  backing.  The  riveting  is  l)est 
done  with  punch  forceps  having 
a  large  punch,  the  porcelain  front 
being  protected  by  a  })iece  of  lead  placed  against  the  labial  aspect 
(Fig.  359).  The  heads  on  the  pins  should  then  be  burnished 
smooth  with  a  revolving  burnisher. 

Bridge-work  can  be  made  with  replaceable  porcelain  fronts 
which  can  be  easily  substituted  in  case  of  fracture.  A  descrip- 
tion of  their  application  will  l)e  found  at  page  160. 

If  the  character  of  the  breakage  is  such  as  will  not  permit  its 
170 


REPAIR  OF  CROWN-  OR  BRIDGE-WORK.  171 

re[)air  in  tlie  mouth,  the  l^ndu'e  must  l)e  reuioved  for  the  pur- 
pose and  tlien  re-inserted.  Under  such  eireumstanees  the  advan- 
taii;es  of  bridii'e-Avork  in  a  detachahk'  form  are  most  evident. 

The  results  foHowiuo:  the  repair  of  single  cr()A\'ns  in  the  UKiuth 
will  seldom  repay  the  labor  attendiuii'  it. 

Removal  of  ('emenfcd  Crowns  and  Bridges. — When  it  1)ecomes 
necessary  to  remove  an  artificial  crown,  whether  inserted  singly 
or  as  a  support  for  a  bridge,  incisors  or  cuspids  are  detached  by 
grinding  the  gold  or  porcelain  away  at  the  palatal  section  over 
the  post,  wdiich  when  exposed  is  severed,  and  the  attachment  of 
the  cement  broken  up.  The  collar  can  also  be  slit  and  bent 
aside  if  found  necessary.  In  an  all-golil  cap  crown  on  a  posterior 
tooth  a  hole  drilled  in  tlie  grinding-surface  will  give  access  to  the 
cement,  a  sufficient  quantity  of  which  can  then  be  removed  to 
loosen  the  attachment;  or,  the  collar  can  be  di^'ided  and  pried 
up  from  the  root  by  first  making  a  groove  with  a  small  rubber 
and  corundum  disk  and  then  cutting  the  gold  with  a  sharp  in- 
strument. "With  care  and  patienee  in  the  operation,  the  crowns 
will  not  usually  be  injured  beyond  repair. 

When  gutta-percha  is  the  cement  that  has  been  used,  a  hot 
instrument  can  be  placed  against  the  metallic  part  of  the  erown, 
or  the  crown  seized  with  the  l)eaks  of  heated  foreeps,  the  gutta- 
pei'cha  tliereby  softened,  and  the  ('ro\\'n  remo\-LMl. 


CHAPTER    VII. 

DETACHABLE  AND  REMOVABLE  BRIDGE-WORK. 

The  evident  advantages  of  bridge-work  have  stimulated  tlie 
inventive  genius  of  dental  mechanists  to  improve  the  method 
and  form  of  its  construction  and  to  extend  its  application. 
With  these  objects  in  view,  some  bridges  have  been  made  so  as 
to  be  easily  detachable  by  the  dentist,  and  others  removable  by 
the  patients  themselves. 

The  construction  of  bridge-work  in  either  of  these  forms 
overcomes  the  chief  objections  to  the  system.  Large  bridges 
are  much  more  easily  made  in  a  detachable  or  removable  form 
than  are  the  smaller  pieces,  which  present  some  of  the  best 
features  of  the  permanently  attached  methods. 

The  following  ingeniously  constructed  bridges  will  serve  to 
illustrate  some  of  the  more  valuable  detachable  and  removable 
methods. 

DR.   WINDER'S    SECTIONAL    CROWN    METHOD. 

This  method,  an  invention  of  Dr.  R.  B.  Winder,  of  Balti- 
more, presents  the  novel  feature  of  constructing  the  crowns  and 
forming  the  abutments  in  sections,  the  bridge  being  attached  to 

the  detaclial)]e  section. 

Fig.  360. 


Fig.  360  illustrates  a  case  of  bridge-work  made  in  this  manner. 
The  collar  section  of  the  artificial  crown  is  capped  and  cemented 
on  the  natural   rrown   or  root,  the  gold  forming  the  occluding 
172 


DETACHABLE  AXD  REMOVABLE  BRIDGE-WORK.  173 


portion  of  the  crown,  when  the  bridge  i^  adjiusted  in  por^ition, 
being  secured  to  it  witli  a  screw.  The  screw  may  be  made  to 
enter  tlie  body  of  the  erown  as  is  shown  by  Fig.  361  or  it  is 

Fig.  361. 


.^ 


1 


Fig.  362. 


Fig.  368. 


Fig.  364. 


sohlered  to  the  cap  on  the  colhir,  jiassing  through  the  occluding 
section  of  the  crown,  and  secured  by  nuts 
on  the  screws  as  illustrated  by  Fig.  362. 

When  iueisor  or  cuspid  roots  form  the 
abutments,  Dr.  Winder  first  forms  a  cap 
for  the  end  of  the  root,  to  wliieh  a  tube 
is  attached  extending  up  the  root-canal  as 
seen  at  A,  in  Fig.  363.  On  this  cap  is 
mounted  the  crown  (B),  the  post  of  which 
fits  the  tube  tightly.  To  the  crown  so 
formed  (Fig.  364)  the  britlge  is  joined  in 
tlie  usual  manner. 

In  constructing  a  bridge  of  this  style, 
the  crowns  forming  the  abutments  having 
first  been  made,  are  removed  from  the 
mouth  in  a  plaster  impression  and  articulation,  from  which  a 


174  ARTIFICIAL  CROWN-  AND  BRIDGE  WORK. 

model  is  made,  showing  the  crowns  in  position.  Each  section 
of  the  bridge  between  the  crowns  is  then  constructed,  and  the 
crowns  adjusted  in  the  mouth.  The  bridges  are  next  inserted  in 
position,  and  cemented  with  resin  and  wax  to  the  detachable 
sections  of  the  crowns.  The  wdiole  is  then  removed  in  investing 
material,  in  an  impression-cup,  or  by  placing  the  investing  material 
in  position  on  the  bridge.  After  being  removed  from  the  mouth 
more  investing  material  is  added  and  the  bridge  and  crown 
sections  soldered  together.  Only  the  detachable  sections  of  the 
crowns  should  be  in  the  investment  in  the  operation  of  soldering. 

AVhen  the  bridge  is  finished  the  root  and  collar  section  of 
each  crown  is  first  cemented  on  in  position  in  the  mouth ;  the 
surface  of  the  detachable  section  of  the  crown  approximating 
the  section  fastened  to  the  bridge  is  then  heated  and  its  surface 
covered  with  a  mere  film  of  gutta-percha.  The  bridge  is  then 
adjusted  in  position  and  secured  by  the  screws  or  nuts.  The 
gutta-percha  prevents  the  secretions  invading  the  interstices 
between  the  sections  of  the  crown. 

The  incisive  edges  can  be  protected  and  the  occluding  surfaces 
of  the  porcelain  capped  with  gold  as  in  permanently  aitached 
bridge-work,  or  they  can  be  formed  of  the  porcelain,  which 
lessens  the  labor  of  construction,  as  the  bridge  is  easily  detached 
from  the  abutments  for  the  purpose  of  repair. 

A  decided  advantage  possessed  by  this  method  of  bridge- 
work  over  others  in  practice  is  the  facility  it  afl:brds  for  the 
ready  utilization  of  irregular  teeth  as  abutments,  no  matter  how 
nmch  they  converge  or  diverge,  or  lean  in  or  out  of  the  line  of 
the  arch. 

DR.     LITCH'S    METHOD. 

Dr.  Liteh's  method  of  constructing  detaeha])le  bridge-work 
consists  in  forming  a  shell  anclKn'age  over  posts  permanently 
fixed  on  cuspid  roots,  and  anchoring  the  ends  of  the  bridge  with 
l)ars  in  slots  formed  in  natural  or  artificial  crowns. 

Figs.  365,  3tJ6,  and  367  illustrate  a  bridge  similar  to  the  one 
illustrate<l  in  Fig.  291  with  this  style  of  attachment  applied. 
The  anchorage  for  the  cuspids  is  constructed  as  follows:  The 
root  is  first  capped  and  pivoted  as  for  a  collar  crown.  On  tlie 
palatal  portion  of  the  collar  is  soldered  a  flange  (A,  Fig.  368) 


DETACHABLE  AND  REMOVABLE  BRIDGE- U'OBK. 


17  b 


made  oi'  u'olil,  Xo.  16  U.  S.  standard  gautce,  beveled  oft"  to  the 
upper  edge  of  the  eohar  under  the  free  edge  of  the  gum,  the 
object  being  to  give  a  hirger  surface  to  the  top  of  the  cap.  On 
this  ca}),  \vliieh  covers  the  end  of  the  root,  the  ancliorage  jiost 


Fig.  365. 


Fig.  366. 


Fig.  36' 


Fig.  368. 


B,  which  is  formed  of  iridio-]»latinum  wire,  No.  9  U.  S.  standard 
gauge,  is  sohlered,  over  and  l)ack  of  the  pin  (C)  Avliieh  enters 
the  root-canal,  so  as  to  allow  room  for  the  jioreelain  front  D. 
The  porcelain   front  is  ground   in   proper  position  on  this  caii. 


176 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


backed,  attaelied  with  resin  and  wax,  and  removed  witli  the  cap. 
The  cap  is  next  invested  in  plaster  to  the  edge  of  the  cohar,  and 
a  little  plaster  placed  on  the  labial  aspect  of  the  porcelain  front 
in  the  form  of  a  matrix,  so  as  to  allow  the  porcelain  to  be 
removed  and  replaced,  A  piece  of  heavy  iridio-platinnm  plate 
(E),  No.  16  U.  S.  standard  gauge,  is  then  shaped  into  the  form 
of  a  half-ring,  with  the  ends  of  the  plate  against  the  backing  of 
the  porcelain  front,  and  of  sufficient  size  to  rest  on  the  flanged 
edge  of  the  cap  when  completed.  On  the  outside  of  this  half- 
ring  is  fitted  and  soldered  a  thin  strip  of  gold,  F,  of  No.  28 
U.  S.  standard  gauge,  Avhich  will  cover  the  half-ring  and  extend 
l)eyond  its  up;[)er  margin,  slightly  overlapping  the  flange  of  the 
collar  (G).  This  forms  a  brace  or  edge  on  the  anchorage  cap  as 
it  rests  on  the  root-cap.  The  half-ring  is  then  fitted  to  the  tooth, 
attached  with  wax,  and  removed  with  the  tooth  out  of  the  plaster 
matrix  from  the  root-cap,  invested,  and  securely  soldered  on  the 
inside  to  the  backing  of  the  tooth.  The  tooth  and  half-ring  are 
then  adjusted  to  the  root-cap,  over  the  post  of  which  the  ring 
must  slide  easily  (Fig.  369).  To  this  ring  the  bridge  is  soldered 
the  same  as  to  a  crown. 

When  the  bridge  is  inserted,  the  cap  for  the  root,  with 
the  post,  is  first  cemented  on  with  oxyphosphate.  After 
the  cement  has  set,  the  anchorage  ring  is  filled  with  more 
cement  and  pressed  into  position  upon  the  cap  over  the 
anchorage  post.  The  surface  of  the  cement  (H,  Fig. 
368)  can  ])e  protected  by  a  metallic  filling. 

This  form  of  attachment  permits  the  bridge  to  be 
easily  removed  by  attbrding  access  to  the  cement  around 
the  pin.  The  bar  ends  of  the  bridge  are  anchored  in 
the  crowns  with  gold  or  amalgam  fillings,  which  like- 
wise are  not  difficult  to  remove. 

The  anchorage  cavity  for  a  bar  in  a  gold  crown  for 
use  over  a  tooth  with  a  living  pulp  is  best  made  by 
cutting  out  the  gold  to  the  form  of  the  slot  required,  and  inserting 
in  its  place  a  piece  of  platinum  the  shape  of  the  walls  of  the 
anchorage  cavity.  The  crown  is  then  filled  with  investing 
material,  and  the  metal  forming  the  anchorage  cavity  soldered  to 
the  crown  at  the  edges  of  the  cavity. 


Fig.  369. 


DETACHABLE  AND  REMOVABLE  BRIDGE- WORK. 


177 


DR.    R.    W.    STARR'S     METHODS. 

Dr.  K.  AValttT  StaiT.  of  Philadc'li»liia,  uives  tin-  following 
deseri[»ti()iis  of  his  methods  in  detachahlo  bri<lge-\v(»rk : 

"  The  ease  of  Mr.  W.  })resentcd  diffieulties  of  an  unnsual 
cliaraeter,  as  may  be  seen  \)\  inspecting  the  illustration.  Fig.  370, 
which  renders  detailed  description  unnecessary. 

'■'■  It  will  l)e  observed  that  the  molars  and  the  left  second  bicus[»id 
overliang  to  a  degree  that  woidd  make  the  taking  of  an  accurate 

Fig.  370. 


impression  by  ordinary  methods  well-nigh  inijxissible.  After  a 
careful  stndy  of  tlie  case,  it  was  decided  that  two  separate  pieces 
of  detachable  bridge-work  should  be  attempted,  and,  as  an 
essential  preliminary  ste]t,  the  overhanging  sides  of  the  molars 
and  bicuspids  were  ground  with  engine  corundum-wheels  and 
points  until  those  sides  were  made  much  less  inclined,  when 
j)laster  im]>ressions  were  taken,  first  of  one  lialf,  and  then  of 
the  (^ther  half,  of  the  jaw.  Gold  i-a})  erowns  were  closely  fitted 
over  the  niolai's.  left  second  bicuspid,  right  first  bicuspid,  and 
cuspid  stump.  Gold  t-rowns  were  made  to  telescope  over  all  the 
caps,  which  were  then,  by  means  of  oxyphosphate  cement, 
fixed  firmly  on  the  teeth.     Suitable  jilate  teeth  were  selected, 

12 


178 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


fitted,  backed,  and  liard-waxed  in  place  between  the  telescoping 
crowns.  After  hardening  the  wax  with  cold  water  from  a  tooth- 
syringe,  the  pieces  were  careftilly  removed,  invested,  and  soldered. 
The  two  completed  bridges  were  easily  replaced  on  or  removed 
from  the  supporting  capped  teeth,  and  their  appearance  when 
detached  is  correctly  shown  by  the  illustration,  Fig.  371,  which 
also  shows  the  capped  teeth  and  stumps.  The  figure  likewise 
shows  the  results  of  the  novel  method  employed  in  crowning 

Fig.  371. 


the  incisors.  Gold  collars  were  fitted  tight  on  the  necks  of  the 
incisor  stumps,  and  the  new-style  porcelain  caps  adjusted  in  the 
collars,  and  set  in  the  oxyphosphate  cement  which  had  been 
packed  into  the  collars;  thus  at  the  same  time  fastening  the 
collars  on  the  stumps  and  the  caps  in  the  collars,  as  shown 
completed  in  Figs.  371  and  372. 

"  Fig.  372  illustrates  the  finished  crowns  and  bridges,  which 
latter  were  secured  in  position  by  placing  a  small  piece  of  gutta- 
percha in  each  of  the  telescoping  cap  crowns,  which  were  then 
warmed  and  carefully  pressed  in  place, — the  gutta-percha  filling 


DETACHABLE  AND  REMOVABLE  BRIDGE- WOJRK. 


179 


only  tlie  spaces  between  tlie  Hat  toi)S  of  the  caps  of  tlic  natural 
teeth  and  cusped  caps  of  the  bridges. 

"Whenever,  for  repair  or  for  any  other  purpose,  it  shall  be- 
come desirable  to  remove  one  of  the  bridges,  that  may  readily 
be  done  by  applying  a  hot  instrument  or  hot  air  to  the  caps  to 
soften  the  gutta-percha  sufficiently  to  permit  the  telescoping 
bridge  to  be  taken  off. 

"  A  full  u})per  vulcanite  denture  was  made  to  replace  the  old 
one,  which,  1)y  iiu[)roper  occlusion,  had  thrown  tlie  full  force  of 
mastication  on  the  anterior  teeth  of  the  lower  jaw,  and  produced 

Fig.  372.  Fig.  873. 


'  ""iiUUlllllllllllillillllllllllli!. 


the  destructive   action   that  resulted  in  the   deplorable  loss  of 
tooth-substance  shown  in  Fig.  370."^ 

The  next  case  also  presented  unusual  difficulties.  "The  forward 
overhang  of  the  inferior  right  second  molar  was  so  excessive  that 
an  impression  could  hardly  be  taken,  until  with  corundum-wheels 
and  points  the  sides  of  the  tooth  had  been  nnide  parallel,  or 
rather  slightly  tapering  to  form  a  truncated  cone,  Avith  the  neck 
as  a  base.  The  molar  was  ali\e  and  sound,  but  the  crown  was 
gone  from  the  pulpless  cuspid,  which  I  8uital)ly  shaped  by  means 
of  my  root-trimmers  (Fig.  373). 


^Dental  Cos»ws,  vol.  xxviii,  No.  1,  page  17. 


180 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


"  All  impression  Wt^s  then  taken,  the  cast  from  which  is  ilhis- 
trated  by  Fig.  374.  A  seamless  gold  collar  was,  hy  means  of  a 
slightly  tapering  mandrel,  made  to  exactly  fit  the  tapered  natural 
molar,  the  lower  edge  of  the  collar  cut  to  conform  to  the  gin- 
gival margin ;  a  cap  piece  of  gold  plate  soldered  to  the  top  edge 
of  the  collar,  and  a  hole  drilled  through  the  center  of  the  com- 
pleted cap  (A,  Fig.  374).  Care  was  taken  to  so  fit  and  proportion 
the  cap  that  it  would  require  finally  pretty  hard  driving  to  send  it 
home  on  the  tooth ;  hut  first  there  Avas  fitted  to  the  cap  a  telescojv 
ing  seamless  collar,  on  which  was  soldered  a  gold  plate,  with  cusps, 

Fig.  374. 


to  form  a  molar  crown  as  shown  in  Fig.  374.  The  molar  was 
then  thorougldy  dried,  slightly  i)aiiited  Avith  Agate  cement,  and 
the  cap.  A,  driven  hard  down  with  a  flat  pine  stick  held  u[»on  it 
and  struck  with  a  mallet;  the  hole  in  the  cap  enabling  me  to  see 
when  the  cap  was  quite  down.  The  cuspid  was  then  likewise 
fitted  with  a  seamless  gold  collar,  the  top  edge  of  Avhich  was 
given  a  roof-shape,  as  seen  above  the  root  in  Fig.  374.  A  piece 
of  gold  received  a  corresponding  roof-shape,  had  a  short  section 
of  gold  tubing  soldered  into  it,  and  was  trimmed  to  the  outline 
of  the  collar,  l)eside  which,  B,  Fig.  374,  its  form  is  seen,  and  to 
AN'hich  it  was  subsequently  soldered,  after  suitable  investment  to 
keep  the  parts  in  t>roper  place.     The  root-canal  had  been  pre- 


DETACHABLE  AND  REMOVABLE  BRIDGE-WORK. 


181 


viouslv  prejiared  to  receive  the  tube,  which,  with  its  roofed  cap, 
was  with  stick  and  mallet  driven  hard  down  over  the  root.  A 
piece  of  gold  wire  exactly  fitting  the  tube  had  a  roof-shaped 
piece  of  properly-perforated  gold  plate  slipped  over  it  into  posi- 
tion on  the  root;  became  fixed  in  such  relation  by  a  drop  of 
melted  hard  wax  ;  was  removed,  invested,  soldered,  and  finished 
in  such  shape  that,  excepting  the  hollowness,  it  looked  like  tlie 
tube  and  cap  B. 

"The  relations  of  the  occluding  teeth  had,  of  course,  been 
determined  by  an  articulating  model,  and  by  means  of  it  a  series 
of  seamless  gold  collars  and  cusp-crowns  were  adjusted  on  a  thin 
platinum  plate  fitted  on  the  cast  between  the  cuspid  and  second 
molar,  and  the  collars  soldered  to  the  plate   after  investment. 

Fig.  375. 


The  truss  thus  formed  received  an  appropriate  finish  l)y  the 
rounding  and  smoothing  of  its  basal  borders.  A  jilain  plate 
cuspid  was  backed  with  gold  plate  and  fitted  on  the  roof-plate,  to 
which,  after  determining  its  proper  occlusion,  it  was  secured  by 
hard  wax;  removed,  invested,  and  soldered.  It  was  then  put 
into  the  tube  on  the  I'oot ;  the  telescoping  cai»  put  over  the  molar ; 
the  truss  put  in  ]>osition  in  the  mouth,  and  the  whole  covered 
with  plaster  and  marble-dust,  contained  in  a  suitabk-  sectional 
impression-tray,  which  enabled  me  to  hold  the  mass  steadily  in 
place  until  the  mixture  was  sufiiciently  hard  to  bring  away  cap 
and  truss  and  roof-plat^'  all  in  pi-oper  ]t(tsition.  A  second  mixture 
of  |)laster  and  marble-dust,  and  a  suitabk'  trimming  of  the  first 
mixture  after  all  was  hard,  sutHced  for  the  soldering  process  that 


182 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


Fig.  376. 


resulted  in  the  denture  which,  when  finished,  appeared  as  shown 
detached  at  C,  and  mounted  on  the  cast  in  Fig.  375.  It  went 
firmly  to  place  in  the  mouth,  and  yet  was  removable  in  the 
possible  event  of  accident  to  the  denture,  or  for  readjustment  of 
the  cusp-crowns,  which  latter  could  easily  be  done  by  warming 
the  piece  sufiiciently  to  soften  the  gutta-percha,  replacing  the 
denture  on  its  anchorages,  and  directing  the  proper  closure  of  the 
occluding  teeth. 

DR.    C.    M.    RICHMOND'S     METHOD. 

"  Dr.  C.  M.  "Richmond,  of  ISaw  York  City,  in  making  remov- 
able dentures  of  the  entirely  soldered  kind,  emplo_ys  a  zinc  die 
made  from  a  cast  of  the  anchor  tooth  with  its  cap  on.  He 
makes  of  crown  metal  (platinum  faced  with  gold)  a  collar  some- 
what smaller  than  the  tooth-cap,  and  deep  enough  to  reach  from 
the  gum  to  about  a  sixteenth  of  an  inch  above  the  cap.     He  then 

drives  the  die  into  the  collar  so  far 
that  the  extra  sixteenth  of  an  inch 
can  be  hammered  over  and  burnished 
down  on  the  die-end  to  form  a 
flanged  collar.  Outside  of  this,  in 
the  same  manner,  he  forms  another 
flanged  collar,  and  then  solders  the 
two  together,  thus  obtaining  a  close- 
titting,  stiff"  collar,  that  will  not 
stretch  in  l)eing  telescoped  on  and  off"  the  anchorage,  and  is  kept 
by  the  flange  from  being  forced  too  far  over  the  tooth-cap.  A 
denture  of  this  kind  is  illustrated  in  Fig.  376,  which  also  shoAVS 
his  post  and  roof  device  in  another  form  than  that  previously 
described."  ^ 

DR.    T.    S.    WATERS'S    METHOD. 

Figs.  377  and  378  represent  a  case  of  removable  bridge-work 
by  Dr.  T.  S.  Waters,  of  Baltimore,  and  will  illustrate  his  methods. 
Tiie  natural  molar  and  bicuspid  are  capped  with  gold  crowns, 
the  molar  being  double-capped.  The  outer  cap  contains  two 
small  springs  on  the  inside  surface  (see  outline  molar),  which 
firmly  retain  it  by  their  pressure  on  the  sides  of  the  inner  cap. 


'  Dental  Cosmos,  vol.  xxviii,  No.  8,  page  497. 


DETACHABLE  AND  REMOVABLE  BRIDGE-WORK. 


183 


The  l)ancl  for  the  bicuspid  crown  has  two  shoulders  on  the  inside 
which  fit  into  o-rooves  cut  in  the  mesial  and  distal  sides  of  the 


Fig.  3i 


n  ffl 


Fig.  378. 


gold  forming   the  crown.      Fig.   378   represents  the  lu'idge   in 
position. 

DR.    PARR'S     METHODS. 

Detarhahle.—F'ig.  379  illustrates  a  method  of  this  style.     The 
bridge  is  sup})()rted  between  the  abutments,  which  lean  towards 

Fig.  379. 


each  other  |)()st('ri(>rly  and  nnt<.'riorly  owr  thi'  spare'  to  l)c' bridgL'd, 
as  shown  on  the  original  niode'l.  Fig.  380,  by  two  shoulders  on 
the  crowns  which  sli<lc  into  groows^jformed  in  the  dummies  (Fig. 
381).     These  supporting  shoulders  and  .><lots  are  made  by  sha]iing 


184 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


two  pieces  of  plate  to  the  form  shown  in  Fig.  382,  so  that  one  shall 
telescope  the  other.  The  inner  one  is  then  invested  on  the  out- 
side surface  and  filled  in  with  gold  plate.  The  outer  piece  is 
then  filled  inside  with  investing  material,  and  gold  plate  is  flowed 
over  the  outer  surface.  The  shoulders  are  first  soldered  to  the 
crowns,  and  afterward  the  slots  are  adjusted  to  them  and  soldered 
in  position  in  the  bridge. 


Fig.  380. 


Fig.  381. 


Removable  Sectional  Bj-idf/e. — In  this  style  the  croAvns  forming 
the  abutments  are  permanently  cemented  in  position,  each  section 
of  the  bridge  l)etween  them  being  removable.  The  case  illus- 
trated in  Fig.  383  will  serve  as  a  type  to  give  the  constructive 
details.  The  cuspid  and  molar  crowns  are  first  formed  in  the 
usual  manner.     A  model  from  an  impression  is  then  made  on 

Fig.  383. 


which  the  crowns  will  be  in  the  same  position  as  in  the  mouth. 
A  gold  and  platinum  bar  (A,  Fig.  384)  is  then  formed  between 
the  cuspid  and  molar.  The  end  for  the  cuspid  is  rounded,  and 
that  for  the  molar  flattened.  'I'his  last  may  be  done  by  hammer- 
ing the  wire  flat  or  by  soldering  a  piece  of  clas])  plate  trans- 
versely to  it.     The  two  ends  of  the  bar  are  then  fitted  in  tubes  (^f 


DETACHABLE  AND  REMOVABLE  BRIDGE- WORK. 


185 


Fig.  384. 


|ilatininii  (B,  B),  and  the  tubes  are  soldered  to  the  sides  of  tlie 

cuspid  and  molar  crowns  (A,  A,  Fig.  383).     If  jiret'erred,  the  slot 

on   the  side  of  the  m(dar  crown   can  be  made  with  a  piece  of 

platinum  adapted  over  the  flat  piece  of  gold  forming  the  end  of 

the  bar  and  then  soldering  the  platinum  to  the  side  of  the  crown. 

At  this  point  the  crowns  and  bar  should 

be   adjusted  in   the  mouth,  as  well    as 

on  the  model,  to  insure  accuracy.     To 

this  l)ar  the  teeth  constituting  the  bridge 

are  fitted  in  their  respective   positions 

and  soldered.     Bending  either  end  of 

the  bar  slightly  (B,  B,  Fig.  383)  or  sawing  a  slit  in  the  cuspid 

end  of  it  (Fig.  391),  afford  the  means  of  holding  the  bridge 

firmly  in  position,  Avhile  it  may  be  removed  and  reinserted  at  the 

option  of  its  wearer.     Fig.  385  shows  the  inserted  bridge. 

Fig.  386  shows  another  method  of  forming  a  socket  attach- 
ment. In  the  figure,  the  socket  section  of  the  attachment  is 
seen  projecting  from  the  side  of  the  molar  crown.     The  other 


Fig.  385. 


Fig.  386. 


section  I'onsists  of  a  cai)  liaviiio-  a  si)rinii'  fiancee.  The  fian^'e 
enters  the  socket,  AX'hich  the  cap  incloses  on  the  top  and  sides. 
The  spring  is  made  by  cutting  tlie  part  of  the  flange  marked  A 
crosswise  and  d<nvn wards  as  marked  by  the  dotted  line,  and 
bending  it  a  little  to  one  side.  The  gold  caps  forming  the 
occluding  surface  of  the  bridge  teeth  or  "•  dummies  "  are  adjusted 
over  and  soldered  to  the  cap  section  of  the  attachment. 

In  a  bridge  of  this  style  of  the  anterior  teeth  only, — where 
the  abutments  form  tlu'  extremities  of  the  }iiece, — the  ends  should 
be  attaclied  to  the  mesial  sides  of  the  crowns  forming  the  sup- 
ports; but  when  it  also  carries  teeth  i)Osterior  to  the  abutment, 


186 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


Fig.  387. 


Fig.  3^8. 


the  attachment  shouhl  be  made  on  the  distal  t^ide,  the  Ijar  wup- 
].iorting  the  anterior  teeth  restino-  in  a  slot  formed  on  the  jjalatal 
side  of  the  abutment  (Fig.  387).  A  shell  crown  on  a  cuspid  can 
be  utilized  as  a  support  for  this  form  of  attachment. 

Fig.  388  illustrates  a  removable  cuspid  crown  which  can  be 
used  in  removable  bridge-work.  It  is  constructed  as  follows : 
The  end  of  the  root  is  first  capped.  A  porcelain  cross-pin 
tootli,  tlie  pins  of  which  are  set  well  apart,  is  then  ground  and 
adjusted  in  position,  cemented  with  wax  to  the  cap,  and  both 
removed.  Enough  ;[;ilaster  to  form  a  matrix  is  placed  on  the 
labial  aspect  of  the  porcelain  and 
collar  to  hold  them  in  relative  posi- 
tion when  the  wax  is  removed.  A 
fl-^^f  post  iaithen  formed  on  the  root- 
c|p,  cxWimng  from  the  labial  edge 
forwjMU^etween  the  pins  of  the  tooth, 
tlie  porcelain  of  which,  between  the 
pins,  should  l)e  slightly  cut  out  to 
receive  it.  To  this  is  soldered  the  piece  A  which  is 
to  act  as  a  spring.  The  post  is  formed  of  plate  ISTo. 
18  U.  S.  standard  gauge,  and  the  s}»ring  of  clasp  gold 
No.  26.  The  post  is  soldered  to  the  cap  from  the 
opposite  side  to  the  spring  l)y  investing  without  the 
tooth.  The  tcjoth  is  then  lined  with  very  thin  plati- 
num and  with  the  aid  of  the  matrix  is  adjusted  in  posi- 
tion on  the  cap,  and  a  thin  piece  of  platinum  plate  is 
slit  at  the  edges  and  adapted  over  the  post,  cap,  and  edge  of  the 
collar,  witli  its  inner  edge  meeting  the  backing  of  the  tooth. 
The  platinum  plate  is  then  cemented  with  wax  to  the  l)acking 
on  the  tooth,  removed  with  it  from  the  cap  and  post,  and  in- 
vested, the  slot  for  the  post  being  carefully  filled  with  the  invest- 
ing material.  Gold  plate  is  then  flowed  over  the  plate  and 
backing  so  as  to  consolidate  the  parts  in  one  piece. 

This  crown  when  finished  will  fit  on  to  the  cap  and  post,  the 
spring  of  which  can  l)e  bent  to  securely  retain  it.  The  line  of 
the  post  on  the  cap  as  it  fits  in  the  slot  in  the  croAvn  should  ])e 
snch  as  will  favor  the  insertion  and  removal  of  the  bridge. 


CHAPTER    VIII. 


REMOVABLE    PLATE    BRIDGES. 

In  tliis  stvk'  of  britlii-e  a  plate  is  used  to  span  the  space 
and  support  the  artificial  teeth  between  the  abutments.  A  prime 
recjuisite  of  rcm(M'al)le  plate  brido-es  is  that  the  posts  and  collars 
or  any  form  of  attachments  used  shall  move  evenly  on  and  off 
the  su])itortinii-  roots  or  crowns  in  their  adjustment  and  removal. 
To  secure  this,  the  post-cavities  and  crowns  should  be  sha]>ed 
and  the  gold  crowns  formed  so 

that  tlie  lines  of  the   center  of  ^^*^-  ''^^■ 

the  cavities  and  of  the  sides  of 
the  gold  crowns  shall  be  as 
nearly  as  ])ossib]e  parallel.  To 
facilitate  tlie  ojteration,  })osts  of 
wood  or  metal  should  be  first 
accui'ately  but  loosely  inserted  in 
the  root-canals,  protrudinu'  a 
([uarter  of  an  inch,  and  an  im- 
pression taken.  On  the  model 
made  from  this  impression  the 
])osts  will  l)c  found  in  position 
as  in  the  moutli.  The  ])laster 
crowns  are  thcu  trimmed  to  the  required  f>rm.  Gutta-percha  or 
im[)i'ession  com])oun(l,  fitted  to  the  model  and  removed  with  the 
posts  in  position  in  it,  can  then  be  used  to  guide  the  operator, 
and  gang*'  the  preparation  of  teeth  or  roots  in  the  mouth. 

The  case  shown  in  Fig.  38U  will  be  taken  to  descril)e  the  con- 
structive details  of  this  class  of  dentures.  In  the  root  of  the 
central  a  tube  is  inserted,  attached  to  a  cap  on  the  end  of  the 
root.  Over  this  cap  is  [)laced  an  outer  cap  which  has  a  split 
spring  pivot  or  post  fitting  the  tube.     A  narrow  plate  between 

187 


188 


ARTIFICIAL  CROWN-  AND  BRIDGE- WORK. 


the  teeth  connects  the  outer  cap  to  a  clasp  which  fits  around 
and  rests  upon  the  cuspid. 

The  2)rocess  of  construction  is  as  follows, — the  method  being 
similar  when  applied  to  larger  dentures  of  this  class  :  The  root 
of  the  central  is  first  prepared  and  capped  the  same  as  for  a  collar 
crown.  The  cap  is  best  formed  of  iridio-platinum  plate,  No.  35 
U.  S,  standard  gauge  (A,  Fig.  390).  A  substantial  piece  of  gold 
and  platinum  wire,  from  No.  16  t(^  No.  18  U.  S.  standard  gauge 
(the  number  being  regulated  by  the  size  of  the  root),  is  slit  about 
one-eighth  of  an  incli  so  as  to  form  a  spring-post  or  pivot.  This 
is  easily  done  l)y  placing  the  wire  in  a  vise  and  steadily  cutting 
it  downward  through  the  center  with  a  saw-edged  strip  of  very 
thin  steel  (Fig.  391).  This  takes  only  a  few  minutes,  and  is 
preferable  to  partially  jcnning  two  pieces  of  half-round  wire. 


Fig.  390. 


A 

^5 


r» 


Fig.  391. 


The  wire  is  then  tapped  together  at  the  slit,  burnished  smooth  and 
rounded  just  at  the  end  (B,  Fig,  390).  The  tube  for  this  pivot  is 
formed  by  once  encircling  the  pivot  with  a  piece  of  iridio-i)lati- 
num  plate,  No.  32  U.  S.  standard  gauge,  the  edge  of  which  is 
beveled  and  cut  to  meet  the  plate  even  and  close  (C).  The  })ivot 
is  then  withdrawn,  and  the  seam  is  touched  along  its  length  with 
the  smallest  possible  quantity  of  borax.  The  proper  manner  to 
use  borax  in  fine  work  is  to  grind  it,  mixed  with  water,  on  a  slab 
to  a  cream-like  consistence,  and  apply  on  thejioint  of  a  camel's- 
hair  brush.  A  very  small  piece  oi'  pure  gold  is  placed  in  the 
seam,  and  the  tube  is  held  in  the  flame  of  an  alcohol  lamp. 
When  a  sufficient  degree  of  heat  is  reached,  the  gold  will  flow 
along  the  seam  and  form  a  joint  without  obstructing  the  inside 
passage  for  the  pivot.     The  pivot  is  then  inserted,  and  the  tube 


REMOVABLE  PLATE  BRIDGES. 


189 


trimmed  (D)  and  gaiiiivd  in  a  ganu'e-piate'.  With  a  drill  just 
the  size  of  the  tube  tlie  root-canal  is  enlarged  so  that  the  tuhe 
\\'ill  fit  in  tightly.  "^I'liis  plan  prevents  weakening  of  the  root 
by  too  great  enlargement  of  the  canal.  A  hole  the  size  of  the 
tube  is  made  through  the  cap,  and  they  are  then  adjusted  (Fig. 
392),  and  the  ])ivot  l)eing  withdrawn,  the  ca[)  and  tuhe  are  re- 
moved, invested,  and  soldered  (A,  Fig.  393).  The  cuspid,  which 
because  of  its  conical  fornuition  is  one  of  the  most  dithcult  teeth 
in  the  mouth  to  clasp,  is  trimmed  sutliciently  to  partially  s(pnire 
its  ap[)roximal  sides,  and  the  palatal  portion  is  notched  slightly 

Fig.  392. 


■L_i 


(A,  Fig.  394),  to  form  a  shoulder  for  the  clasp  to  rest  ujton. 
This  notch  can  be  safely  made,  as  the  enamel  is  very  dense  at 
the  point  indicatech 

A  gold  plate  is  swaged  to  till  the  s[»ace  l)et\\een  the  central 
root  and  the  cuspid  as  shown  in  Fig.  393.  The  cap  and  pivot 
are  adjusted  on  the  central  I'oot  and  the  plate  is  then  titted  in 
the  mouth,  pressed  tightly  in  jxtsition  against  the  ii'um,  and 
retained  there  with  a  little  wax  w  hicli  is  cemented  to  the  plate 
and  jU'essed  against  the  cuspid  and  side  of  the  cap.  An  im- 
pression of  the  [)arts  and  an  articulation  are  then  taken  in 
plaster.  The  cap,  pivot,  and  ])late  being  removed  in  the  im- 
pression, they  will  be  i)resente(l  on  the  model  madi'  from  it  in 
e.Kactly  the  same  position  as  in  the  mouth.  A  second  or  outer 
ca]»  is  then  constructed  f  )r  tln'  root-cap,  the  band  bcinu-  made 
very  narrinv  at  the  approximal   and    palatal   side,  and   open   at 


190 


ARTIFICIAL  CROWN-  AND  BRIDGE- WORK. 


the  labial  side,  as  the  porcelain  tooth  to  be  attached  will  serve  in  its 
stead  (B).  The  pin  is  then  soldered  fast  in  the  onter  ca[),  and  a 
clasp  of  clasp  gold  (C),  No.  23  to  ISTo.  24  U.  S.  standard  gange, 
is  formed  to  extend  well  around  the  posterior  approximal  portion 
of  the  cnspid.  The  onter  cap  having  been  placed  in  position  on 
the  inner  one,  the  plate  extending  from  the  central  to  the 
cuspid  is  cemented  to  it  and  to  the  clasp  with  wax,  removed, 
invested,  and  the  parts  soldered  together.  Aided  by  the  plaster 
articulation,  teeth  are  ground  and  fitted  by  the  model,  backed, 
attached  to  the  plate  with  wax,  aud  inserted  in  the  mouth.  A 
piece  of  platinum  foil  is  then  burnished  to  the  form  of  the 
notch  on  the  cuspid,  the  clasp  fitted  over  it  and  attached  with 
wax,  removed  with  the  plate,  and  soldered  to  it  simultaneously 
with  the  teeth. 

When  the  piece  is  finished  and  fitted  in  the  rnoutli,  the  inner 

Fig.  395. 


cap — the  end  of  the  tube  having  been  closed  with  gutta-percha 
— is  first  cemented  on  the  central  root.  A  very  small  quantity 
of  oxyphosphate  is  used,  and  while  it  is  yet  soft  the  plate  is 
adjuvsted  in  position,  and  allowed  to  remain  there  until  the 
cement  has  set.  The  split  pivot  is  sprung  open  a  little  and 
forced  to  place.  With  the  aid  of  the  clasp  around  the  cuspid, 
it  will  be  found  to  perfectly  secure  the  plate.  Fig.  395  shows  the 
bridge  in  position.  If  the  plate  bridge  is  tightly  adjusted  against 
the  soft  tissues,  and  removed  in  that  position  in  the  impression 
taken  with  the  caps,  it  will  always  be  found  to  fit  in  a  similar 
manner  when  the  bridge  is  finished  and  inserted.  Should  the 
clas}>  cause  decay  or  abi-asion  of  the  cus})id,  the  tooth  can  be 
excavated  to  a  slight  depth  under  the  clasp,  and  filled  with  gold. 
This  is  Ijest  done  by  making  a  few  retaining-})its,  filling  them 
with  a  hand  plugger,  and  then  inserting  the  main  body  of  the 


REMOVABLE  PLATE  BRIDGES. 


191 


gold  hy  the  Herbst  irietliod.  Such  a  filling  inserted  at  any  time 
will  prevent  injnrv  from  a  clasp,  A  denture  of  this  style  can  be 
made  to  pass  intervening  teeth. 

In  the  artificial  rejtlacement  of  the  lower  teeth  in  a  ease  sueh  as 
is  illustrated  in  Fig.  396,  a  plate  l)ridge  possesses  many  advantages. 
In  the  eonstruetion  of  such  a  denture,  the  teeth  are  first  properly 
shaped.  Gold  crowns  (Fig.  397),  the  sides  of  which  are  as  nearly 
as  possible  }»arallel  the  one  with  the  other,  are  then  made  and 
fitted  to  the  bicuspid  and  molar.  On  the  ero\vns,  at  the  buceal 
sides,  a  narrow  shoulder  (A)  is  constructed  to  sustain  the  collars 
and  bridge  in  position.  In  some  cases  this  shoulder  is  placed  on 
the  approxiinal  side  to  better  ad\'antage.     The  crowns  are  then 

Fig.  396. 


adjusted  in  the  mouth,  a  small  quantity  of  wax  being  applied 
inside  of  the  crowns  when  necessary  to  retain  them  in  correct 
position.  A  piece  of  plate  is  next  swaged  and  fitted  between 
the  croAvns  and  attached  with  wax  as  deseribed  in  the  previous 
case.  An  impression  and  articulation  of  that  jiart  of  the  mouth 
are  then  taken  with  plaster  and  the  crowns  and  [)late  removed 
in  it.  On  the  model  made  from  this  impression,  the  crowns 
and  plate  will  appear  in  position.  Collars  reaching  from  the 
cervical  to  the  occluding  edge  are  fitted  to  these  crowns.  They 
are  made  by  first  forming  a  collar  of  ample  width  of  thin 
platinum,  about  Xo.  32  to  No.  34  IT.  S.  standard  gauge,  which 
is  easily  adapted  to  the  form  of  the  crown,  and  on  the  outside 
of  this  fitting  a  slightly  narrower  stri})  of  gold  clasp  plate,  about 
No.  30  V.  S.  standard  gauge.  The  gold  and  jilatinum  are  then 
cemented  with  wax,  removed,  invested,  and  soldered  together 


192 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


with  gold  solder.     A  perfeet-litting  and  reliable  eollar  is  thus 
formed  (B,  Fig.  397). 

The  collars,  though  fitting  accurately,  should  move  easily  oyer 
the  crowns,  as  they  can  l^e  readily  tightened  when  the  case  is 
finished.  If  a  collar  is  troublesome  to  adjust  and  remoye,  cut 
the  side  opposite  to  the  one  attached  to  the  plate,  and  spring  it 
open  a  little.  Atter  the  teeth  haye  been  fitted  it  can  then  be 
ao-ain  united  when  the  teeth  are  being;  soldered.  This  collar  and 
shoulder  form  a  support  preferable  to  a  partial  or  an  entire 
double  cap,  being  less  difficult  to  keep  clean.  A  collar  is  more 
easily  constructed,  and  also  permits  the  position  of  the  bridge  to 

Fig.  397. 


l)e  altered  b}'  the  removal  of  a  little  of  tlie  shoulder  or  f»f  the 
upper  edge  of  the  collar. 

The  collars  and  plate  are  next  cemented  with  wax,  removed, 
invested,  and  strongly  soldered  together  (B,  B,  Fig.  397).  The 
artificial  teeth  are  fitted  in  proper  position  on  the  plate  ])y  the 
aid  of  a  plaster  articulation,  attached  with  wax,  and,  if  preferred, 
adjusted  in  the  mouth  without  the  crowns.  The  bridge  is  then 
invested  and  finished.  The  attachment  of  the  artificial  teeth  to 
the  plate  can  be  of  either  gold  or  rubber.  Whichever  is  adopted, 
the  first  bicuspid  is  best  supported  by  being  soldered  to  the  collar. 
If  iridio-platinum  is  used  in  the  construction  instead  of  gold 
plate,  and  the  soldering  done  Avith  pure  gold,  porcelain  l)ody 
can  1)6  used.  When  ready  to  be  inserted,  the  crowns  are  first 
adjusted  with  cement,  and  then  the  bi-idge,  \\'hich  is  left  in  posi- 
tion until  the  cement  sets.     By  burnishing  the  collars  they  can 


REMOVABLE  PLATE  BRIDGES. 


193 


be  made  to  clasp  the  crowns  as  tirmly  as  desired.     Fig.  398  shows 
the  denture  in  position. 


Fig.  398. 


Figs.  399  and  400  repi^esent  an  upper  removal)le  plate  lu'idge. 
In  its  construction  the  cuspid  roots;  were  first  capped,  tubed  and 


Fig.  399. 


Fig.  400. 


pivoted,  and  the  molars  crowned  with  shoulders  formed  on  the 
buceal  sides.  The  i)late  intended  to  connect  the  abutments  was 
then  adjusted  in  position  as  has  l)een  described.  An  impression 
was  next  taken  and  a  model  and  articulation  made.     The  cuspids 

13 


194 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


were  then  doul)le-ca})ped  and  collars  formed  on  the  molar  crowns. 
The  double  caps,  pivots,  collars,  and  plate  were  next  soldered 
together.     The  artificial  teeth  were  attached  with  vulcanite,  the 


gum'section  being  formed  with  pink. 

Fig.  401. 


In  |the  case  represented  in  Fig.  401  the  natural  teeth  were 
very  short.  The  posterior  approximal  side  of  the  molar  was 
decayed  to  such  an  extent  tliat  the  pulp  was  nearl}'  exposed,  and 


Fig.  402. 


consideralde  irritation    of  the   investing   gum-tissue  had  been 
caused  l)y  the  clasp  of  a  plate  worn   by  the  patient  working 


REMOVABLE  PLATE  BRIDGES. 


195 


upward  against  it.  The  patient  declined  to  have  a  plate  made 
which  woidd  extend  across  the  palate.  Tlic  lateral  was  hardly 
strong  enough  to  support  a  permanent  bridge.  The  molar  was 
capped,  and  a  removable    ai)pliance    constructed  with  a  band 


Fig.  403. 


Fig.  405. 


Fig.  404  rei)rcscnts  a  case  in  which  a  central  incisor  is  re- 
placed on  an  extension  of  the  plate,  the  cuspid  being  partly 
encircled  by  a  cla.sp  with  a  shoulder  resting  on  the  jtalatal  sectioii 
of  the  tooth.     Fig.  405  shows  the  denture  in  position. 


196  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

Fig.  406  represents  a  case  in  which  a  bridge-plate  was  inserted 
without  crowning  either  of  the  abutments.  The  clasp  of  a 
plate  which  had  been  Avorn  for  some  years  had  worked  upward 
and  abraded  the  distal  section  of  the  cuspid  to  such  an  extent 
as  to  expose  a  large  portion  of  the  root  and  superinduce  decay. 
The  cavity  was  tilled  \\'ith  gold,  and  the  gingival  border,  by 
treatment,  brought  nearly  to  its  normal  position  on  the  tooth. 
A  plate  bridge,  such  as  is  represented  in  Figs.  407  and  408,  was 
then  constructed.     Clasps,  with  flanges  resting  on  little  shoulders 


tbrmed  at  A,  A,  Fig.  406,  support  and  retain  it.  A  flange  such 
as  was  used  in  this  case  is  Ijest  made  subsequent  to  the  con- 
struction of  the  Y»late  and  clasps,  by  burnishing  a  piece  of 
platinum  foil  in  the  mouth  to  the  form  of  the  shoulder  and  the 
side  of  a  tooth  upon  which  it  is  to  rest,  adjusting  the  clasp  over 
it,  and  cementing  with  v,  ax,  then  removing,  investing,  and 
soldering.  Wherever  the  platinum  is  placed  the  solder  will  flow 
and  till  all  the  space  between  it  and  the  clasp.  This  gives  the 
exact  form  of  the  tooth. 

Fig.  409  shows  the  denture  finished  and  in  position.     If  the 


REMOVABLE  PLATE  BRIDGES.  197 

teeth  are  dense  in  structure,  an  attachment  of  metal  held  in 
proper  position  against  the  lower  portion  of  a  crown  will  l)e 
worn  a  long  while  hefore  it  causes  injury  to  the  parts.  Filling, 
or  crowning,  if  necessarj^,  can  su])se({uently  be  resorted  to. 

By  a  correct  application  of  the  methods  just  explained  and 
illustrated,  a  piece  of  removahle  l)ridge-work  of  this  style  can 
l>e  devised  for  those  cases  in  whieh  it  is  practicahle.  / 


CHAPTER    IX. 

THE  LOW  BKIDGE. 

Dr.  J.  E.  Low,  of  Cliicago,  is  the  reputed  inventor  of  bridge- 
work  formed  with  self-cleansing  spaces  and  supported  by  means 
of  cemented  collars  or  collar  crowns.-^ 

The  following  is  Dr.  Low's  method  of  using  his  step-plug 
crown  (gee  page  119)  in  conjunction  with  all-gold  cap  crowns 
in  bridge-work.  Fig.  410  shows  a  case  with  the  prepared 
molar  crowns  and  cuspid  roots.  The  bridge  constructed 
according  to  this  method  is  seen  in  Fig.  411,  and  adjusted  in 
position  in  Fig.  412.  Figs.  413,  414,  415  illustrate  a  case  of 
four  incisors  supported  by  two  step-plug  crowns  on  tlie  cuspids. 

Dr.  Low  gives  the  following  instructions  relating  to  the  con- 
struction of  shell  crowns  or  anchorages  on  cuspids,  to  support  a 
bridge  of  the  four  incisors  in  a  case  such  as  is  shown  in  Fig.  416  : 
"  I  first  measure  the  tooth  with  strips  of  tin,  and  make  the  gold 

'The  construction  of  bridge-work  supported  by  collars  or  any  form  of  collar 
crowns  cemented  on  teeth  or  roots,  according  to  a  recent  judicial  decision,  is  not 
at  present  free  to  public  use.  The  two  claims  which  reserve  the  use  of  these 
methods  to  the  inventor  as  specified  in  the  letters  patent  granted,  are  as  follows  : 

"What  I  now  claim  as  new  is:  1.  The  herein-described  method  of  inserting 
and  supporting  artificial  teeth,  which  consists  in  attaching  said  artificial  teeth  to 
continuous  bands  fitted  and  cemented  to  the  adjoining  permanent  teeth,  whereby 
said  artificial  teeth  are  supported  by  said  permanent  teeth  without  dependence 
upon  the  gum  beneath. 

"  2.  An  artificial  tooth  cut  away  at  the  back,  so  as  not  to  present  any  contact 
with  the  gum  except  along  its  front  lower  edge,  and  supported  bj^  rigid  attach- 
ment to  one  or  more  adjoining  permanent  teeth,  substantially  as  and  for  the 
purpose  set  forth." 

A  denture  between  two  or  more  teeth  or  roots,  supported  by  such  means  as  bars 
extending  from  it  anchored  into  teeth  or  caps  or  crowns  which  do  not  encircle  the 
teeth  or  roots,  with  the  artificial  teeth  resting  on  or  pressing  into  the  gums  and 
not  formed  with  what  are  termed  and  described  as  self-clean-ing  spaces,  and 
removable  bridge-work,  are  not,  in  the  opinion  of  experts,  included  in  the  mean- 
ing or  specifications  of  this  patent. — G.  E. 
198 


THE  LO  W  BRIDGE. 


199 


bands  and  cut  out  the  outside  lower  i)ortion  of  the  band  before 
beginning  to  fit.  In  fitting,  as  the  band  is  ])eing  driven  down,  cut 
away  any  of  the  l)and  that  touches  the  gum  before  all  touches; 
never  drive  the  band  under  the  gum,  as  inflammation  will  ])rob- 

FiG    410. 


ably  follow.  1  mention  this,  as  I  have  seen  many  attempts  tojget 
rid  of  the  bands  by  driving  up  under  the  gums  and  cutting  them 
out  on  the  front,  until  they  are  too  narrow  for  strength.       The 


200 


ARTIFICIAL  CROWN-  AND  BRIDGE- WORK. 


bands  should  l^e  heavy  and  strong,  and  the  patient  shoukl  under- 
stand that  if  he  expects  to  get  rid  of  the  annoyance  of  the  plate 
he  must  sacrifice  his  dislike  to  showing  gold.  After  driving  the 
bands  up  close  to  the  margin  of  the  gums,  as  the  cuspid  teeth 
are   very  tapering,  the  l)ands  will   have  to  be  taken  in  at  the 

Fig.  413. 


bottom.  To  do  this  I  slit  the  band  about  a  third  of  its  length 
up,  then  place  it  on  the  tooth  again,  lap  it  over  to  bring  it  to  a 
close  fit,  and  then  take  it  off  and  solder.  Continue  taking  it  in 
wherever  it  docs  not  perfectly  fit  the  tooth,  and  after  a  good  fit 
Fig.  414.  Fio.  415. 


is  obtained  proceed  with  the  construction  of  the  bridge  by  taking 
an  imy)ression  aufd  articulation. 

"  In  adjusting  the  bridge  when  finished  first  try  it  on  to  see  that 
it  fits  and  that  the  articulation  is  all  right.  Fig.  417  shows  the 
case  ready  for  adjustment.     Next  dry  the  teeth  upon  which  the 


THE  LO  W  BRIDGE. 


201 


bands  are  goinii',  and  then  mix  your  cement.  This  should  be 
mixed  to  about  the  consistence  of  thick  cream.  It  must  be 
neither  too  thick  nor  too  thin,  or  tlie  adhesion  will  not  be  strong 
enough  to  hold.     Cover  your  teeth  with  cement,  and  then  the 


Fig.  416. 


inside  of  the  bands.  Place  these  on  the  teeth  and  carefully 
mallet  up  into  position.  For  this  purpose  1  use  a  steel  instru- 
ment with  a  crease  or  groove  in  the  end.  The  teeth  must  be 
kept  dry  after  the  case  is  in  position  until  the  cement  is  well  set. 


Fig.  417. 


Fig.  418. 


After  this  is  done  bevel  the  edges  of  the  bands  and  burnish  close 
to  the  teeth,  and  if  properly  done  they  will  resemble  gold  fill- 
ings. In  Fig.  418  we  have  the  case  completed.  I  always 
impress  upon  my  patients  the  necessity  of  having  the  case  reset 


202 


ARTIFICIAL  GROWN-  AND  BRIDGE-WORK. 


immediately  should  it  l)ecome  loose,  and  advise  them  to  have 
their  case  examined  at  least  once  a  year." 

Dr.  Low  has  invented  for  use  in  crown-  or  bridge-work  a 
ready-made  metallic  socket  or  shell,  into  which  fits  a  correspond- 
ing porcelain  front,  which  can  be  replaced  in  case  of  fracture. 


Fig.  419.. 


Fig.  420. 


Fig.  421. 


Fig.  422. 


Fig.  423. 


Fig.  419  shows  a  socket  shell.  Figs.  420  and  421  represent  a 
socket  with  the  porcelain  in  position.  Fig.  422  represents  the 
socket  as  made  for  the  incisors  and  cuspids,  and  Fig.  423  the 
porcelain  in  position. 


CHAPTER    X. 


DR.    KNAPP'S    METHODS. 


Dr.  J.  RoLLO  Knapp,  of  New  Orleans,  has  introduced  some 
novel  methods  in  crown-  and  bridge-work,  for  etfectiug  artistic 
residts  and  continuity  of  structure. 

In  crown-work.  Dr.  Knapp  invests  for  soldering  so  that  the 
parts  to  be  united  and  tilled  form  a  miniature  mold.  Into  this 
mold,  at  a  high  heat,  with  a  pointed  flame  from  his  blow-pipe, 
he  flows  solder,  whieh  fills  the  interstices,  joins  the  parts,  and 
assumes  the  form  of  the  mold.  The  following  is  a  brief  descrip- 
tion of  his  methods  : 


Fig.  424. 


Fig.  425. 


Fig.  426. 


In  constructing  a  gold  collar  ci'own  with  porcelain  ti-ont,  for 
an  incisor  or  cuspid,  22-carat  The  S.  S.  White  Mfg.  Co.'s  collar 
gold,  No.  28  standard  gauge,  is  used  for  the  collar,  whicb  is  formed 
by  adapting  the  gold  to  tlie  root  by  the  aid  of  pliers.  Tlie  cap  to 
the  band  is  tlien  made  of  i)ure  gold,  No.  34  gauge,  and  a  gold 
[)in  soldered  in  position  for  the  root-canal.  A  plate  tooth  is  then 
ground  in  jiroper  position,  backed  with  pure  gold,  and  fastened 
to  the  cap  with  wax.  On  being  removed  from  tlie  mouth  after 
proper  adjustment,  the  side  and  incisive  portions  of  the  wax, 
including  the  edges  of  tlu'  backing  and  contiguous  portions  of 
the  caj),  are  completely  enveloped  with  pieces  of  jaire  gold  No. 
34  gauge  (Figs.  424  and  42.5).  The  crown  is  then  invested  so 
that  when  the  wax  is  removed  the  l)acking  on  the  tooth  with  tlie 

20:5 


204 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


gold  on  tlie  sides  shall  form  a  small  mold  or  pocket  (Figs.  426 
and  427).  When  the  investment  is  heated,  the  flame  of  his 
l)low-pipe  is  played  over  its  surface  until  the  mass  is  aglow, 
when  the  point  of  the  flame  is  thrown  into  the  mold  by  rapid 
thrusts  until  the  solder  melts  like  wax  and  fills  ever}'  part  of  the 
mold  with  liquid  gold.  This  gives  an  excess  of  gold  which 
aflibrds  ample  facilities  for  contouring  in  the  process  of  finishing 
(Figs.  428  and  429). 


Fig.  427. 


Fig.  428. 


Fig.  429. 


Fig.  430. 


In  constructing  a  bicuspid  crown  with  porcelain  face,  the 
natural  tooth  is  ground  down  to  the  gingival  edge  and  capped 
similar  to  a  cuspid.  A  bicuspid  porcelain  front  is  then  ground 
and  fitted  in  position  (Fig.  430),  and  the  remaining  portion  of 
the  crown  is  shaped  in  wax  to  the  form  required.  A  die  of  the 
grin  ding-surface  is  then  made  in  metal,  a  cap  stamped  in  pure 


Tig.  431.  Fig.  432.  Fig.  433.  Fig.  434.  Fig.  435 


gold,  No.  34  U.  S.  standard  gauge  (Fig.  431),  and  tlie  cusps 
filled  with  20-carat  gold  solder.  This  ca[)  is  next  trimmed  (Fig, 
432)  so  as  to  fit  when  placed  in  pro})er  position  against  the  end 
of  the  porcelain  cusp,  for  which  purpose  suflicient  wax  must  be 
removed.  The  approximal  surfaces  are  enveloped  and  the 
[)alatal  portion  of  the  collar  protected  with  pieces  of  pure  gold 


DR.  KNAPP'S  METHODS. 


205 


No.  34  standard  u'auii-e,  whicli  are  slit  to  facilitate  their  adjust- 
nient  (Fiu'.  433).  This  leaves  the  palatal  jjortion  (»iien  when 
the  crown  is  invested  and  the  wax  removed,  which  last  should  l)e 
done  with  hot  water.  Fiii'.  484  shows  the  invested  crown  ready 
for  soldering,  in  which  operation  the  parts  are  tilled  in  and 
joined  with  20-carat  gold  solder.  The  result  when  finished  is  a 
solid  gold  crown  with  a  porcelain  front  (Fig.  435). 

All-gold  hicuspid  and  molar  crowns  are  formed  bv  Dr.  Knapp 
in  a  similar  manner,  but  as  porcelain  fronts  are  not  used  in 
these  cases,  the  thin  gold  plate  is  placed  entirely  around  the 
lal)ial  aspect  of  the  wax  model.  In  crown-work,  after  the 
cap  has  l)een   made,  an   impression    is    generally   taken   and    a 


Fig.  43(j. 


Fig.  437. 


A 


plaster  model  and  articulation  made  to  facilitate  the  subse(iuent 
construction. 

Dr.  Kna])p's  method  of  constructing  bridge-work  is  similar  to 
that  in  general  use  except  in  the  investing  and  the  soldering  of 
the  parts  together,  the  latter  being  done  with  the  blow-pii)e  in  a 
manner  similar  to  that  alxn^e  described. 

Figs.  43(3  and  437  illustrate  specimens. 

Dr.  Knapp's  compound  blow-pipe  (Fig.  438)  consists  of  a 
miniature  blow-pipe  in  which  the  ordinary  illuminating  gas 
(carburetted  hydrogen  or  coal-gas)  flame  is  combined  with  a 
current  of  nitrous  oxide  from  a  cylinder  of  the  condensed  gas. 
The  combination  of  these  ii'ases  in  combustion  forms  essentially 


206  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

a  carbo-oxy hydrogen  flame/  By  means  of  a  yoke  and  set- 
screw,  the  valve  of  the  cylinder  is  connected  with  the  tubes  and 
valves  of  the  blow-pipe,  so  that  the  proportions  of  the  mixture 

Fig.  438. 


*  The  ordinary  compound  oxyhydrogen  blow-pipe  flame  is  produced  by 
2  volumes  of  hydrogen;  1  volume  of  oxygen. 

Carburetted  hydrogen  consists  of 

2  volumes  of  hydrogen  ;   1  volume  of  carbon. 

And  nitrous  oxide  of 

2  volumes  of  hydrogen  ;   1  volume  of  oxygen. 

Consequently  Knapp's  blow-pipe  flame  is  produced  by  a  mechanical  mixture  of 
2  volumes  of  hydrogen  ;   1  volume  of  oxygen  ;   1  volume  of  carbon. 


DR.  KNAPP'S  METHODS.  207 

of  nitrous  oxide  and  the  illuminating  gases  are  under  }iertect 
control.  The  tiaiue-jet  can  be  diminished  to  half  an  inch  in 
length,  and  at  that  size  will  melt  a  small  piece  of  gold  plate. 

This  blow-[)ipe  is  useful  for  many  purposes  in  the  laboratory  of 
the  present  time,  especially  in  forming  solid  gold  backings  to 
dummies  for  bridge-work,  strengthening  seamless  gold  crowns, 
and  forming  solid  gold  crowns. 

Dr.  Knapp  has  exhibited  to  the  profession  some  very  fine 
specimens  of  erown-  and  bridge-work,  and  presented  much  that 
is  novel  and  interesting,  as  well  as  encouraging  to  the  artistic 
element  of  prosthetic  dentistry.  The  real  value  of  processes  or 
methods,  however,  depends  on  their  practicability.  Therefore, 
in  contemplating  that  which  is  novel  and  beautiful  in  connection 
with  dental  art,  we  must  be  governed  by  this  fact  in  estimating 
its  value.  Judged  from  this  stand-point,  Knapp's  special  methods, 
while  admitting  of  the  highest  artistic  results,  embrace  processes 
which,  on  account  of  their  intricacy,  are  not  likely  to  be  adopted 
in  general  practice. 


CHAPTER   XL 

DR.   MELOTTE'S  METHOD. 

Dr.  G.  W.  Melotte,  of  Ithaca,  N,  Y.,  describes  the  construc- 
tion of  a  bridge  supported  by  a  gold  crown,  and  a  shell  or  par- 
tial gold  crown,  and  the  use  of  his  invention,  "moldine,"  in  con- 
nection with  fusible  metal  in  crown-  and  bridge-work  as  follows  :  ^ 

"  Fig.  439  illustrates  a  case  for  the  supply  of  a  lateral  and  a 

bicuspid.     In  this  instance  the  cuspid  could  be  cut  off,  and  the 

root  collared  and  capped  in  combination  with  a  pin  entering  the 

enlarged  root-canal;  but  as  there  maybe  grounds  for  objection 

to  cuttino;  off  sound  teeth,  I  ob- 
FiG.  439.  .  ,    *  .      ,  '. 

Q  VI ate  the  necessity  by  cuttmg  a 

iiPfjL       shoulder  on  the  lingual  portion 
I  I  I  I  ox 

_,      _~^--/  _J     of    the    cuspid,    and     suitably 

•'^^— ^ ^    shaping  its  sides  to  permit  a  close 

fitting  of  the  collar  just  under 
the  free  margin  of  the  gum.  A  narrow  strip  of  pure  pattern 
tin,  bent  tight  around  the  tooth-neck,  and  cut  through  with  a 
knife  at  the  lap  on  the  labial  surface,  will  serve  as  a  measure  for 
the  length  of  a  strip  of  22-carat  gold  plate,  IsTo.  29  thick,  and  as 
wide  as  the  length  of  the  distal  side  of  the  cuspid.  The  ends  of 
the  gold  are  then  squared,  and  with  round-nosed  pliers  brought 
evenly  together,  to  be  held  in  flush  contact  by  the  soldering- 
clamp  as  shown  in  Fig.  440.  The  soldered  collar,  with  its  joint 
side  inward,  is  then  adjusted  on  the  tooth  as  accurately  as  pos- 
sible, giving  slight  blows  with  a  mallet  until  the  collar  touches 
the  gum,  when  it  should  be  marked  to  indicate  the  necessary 
trimming  to  conform  it  to  the  gum  contour.  After  it  has  been 
thus  trimmed,  the  edges  beveled,  the  labial  part  swelled  with 
contouring  pliers,  and  the  lingual  part  cut  down  to  about  one- 

^  Dental  Cosmos,  vol.  xxviii,  No.  12,  page  745. 
208 


DR.  MELOTTE'S  METHOD. 


209 


tenth  of  an  inch  in  width,  the  collar  is  again  driven  on,  and  will 
appear  as  seen  in  Fig.  439.  A  stump  corundum-wheel  is  then 
used  to  grind  a  shoulder  on  the  lingual  surface  of  the  tooth, 
grinding  also  the  edges  of  the  collar  flush  with  the  shoulder. 
The  collar  is  again  removed,  and  a  piece  of  thin  platinum  plate, 
about  No.  32,  sufficient  to  cover  the  lingual  surface  of  the  tooth, 
is  caught  on  the  lingual  edge  of  the  collar  hy  the  least  bit  of 
solder,  and  all  put  in  place  on  the  cuspid  (Fig.  441).  The 
platinum  should  now  be  burnished  on  to  the  shoulder,  and  over 
the  tooth  and  collar  to  the  extent  shown  by  the  lines  in  Fig.  441. 

Fig.  440. 


Fig.  441.     Fig.  442 


After  trimming  to  those  lines,  and  careful  replacement  and 
burnishing  on  the  tooth,  the  collar  and  half-cap  are  removed, 
tilled  with  wet  plaster  and  marble-dust,  and  the  platinum  soldered 
to  the  gold.  It  is  then  placed  on  the  tooth,  burnished  into  all  the 
ine(iualities  of  the  tooth,  very  carefully  removed,  invested,  and 
enough  solder  flowed  over  the 
platinum  to  cover  and  give  it 
strength.  Fig.  442  shows  it 
complete  on  the  cuspid. 

"  I  have  feared  that  a  detailed 
statement  would  imply  a  long 
and  tedious  process,  but  I  have 
often  made  such  collars  in  less  than  an  hour,  and  in  any  case 
time  must  be  made  subservient  to  exactness  of  fit  and  adaptation 
to  the  end  in  view. 

"  In  the  preparation  for  fitting  a  collar  on  the  first  molar  (Fig. 
439),  I  should  have  wedged  or  otherwise  separated  it  from  the 
second  molar,  so  that  a  piece  of  sheet  brass  might  be  put  in 
place,  as  shown  by  Fig.  443,  and  an  impression  taken  in  plaster, 

14 


^^C 


210  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

whicli  if  allowed  to  get  hard  would  bring  away  the  metal.  If 
not,  it  could  be  replaced  in  the  plaster.  Melted  fusible  metal, 
when  near  the  cooling  point,  is  then  poured  into  the  impression, 
and  when  cold  will  allow  the  safe  removal  of  both  the  plaster 
and  the  metal  strip.  On  this  metal  model  a  collar  can  be  formed 
that  will  accurately  fit  the  molar,  as  seen  in  Fig.  439.  If  the 
molar  has  no  antagonist,  a  cap  maj'  at  once  be  struck  up  on  the 
model;  but  if  there  be  an  antagonist  the  cusps  of  the  natural 
molar  should  be  removed  by  grinding  at  points  where  the 
occluding  tooth  will  admit  of  sufficient  thickness  of  the  gold 
cap.  An  exact  copy  of  the  ground  cusps  can  then  be  made  in 
less  than  five  minutes,  by  the  use  of  moldine  with  its  acces- 
sories, and  the  process  is  as  follows :  Make  the  tooth  perfectly 
dry.  Put  the  collar  on  it.  ISTearh^  fill  the  cup  with  moldine, 
and  coat  it  with  soapstone  powder.  Press  the  compound  on  the 
tooth  and  collar  firmly  to  al)Out  one-fourth  the  depth  of  the 
tooth.  Carefully  remove  the  cup  ;  trim  oflf  any  overhanging 
material,  and  place  the  rubber  ring  over  the  cup  to  about  one- 
half  the  depth  of  the  ring.  Melt  the  fusible  metal  and  pour  it 
as  cool  as  it  will  run  from  the  iron  ladle.  As  soon  as  the  metal 
is  hard,  remove  it  with  the  ring,  taking  care  not  to  impair  the 
impression,  which  can  be  used  again  if  the  die  is  found  imperfect 
or  gets  injured  in  use.  Place  the  die  and  ring  in  cold  water,  to 
remain  until  quite  cooled.  While  the  die  is  wet  and  held  over  a 
basin  of  water,  pour  into  the  ring  fusil  )le  metal  which  has  been 
stirred  until  it  begins  to  granulate,  and  (juickly  immerse  all  in 
the  water.  The  die  and  counter-die  should  separate  readily  by 
tapping  them  with  a  hammer,  but  if  they  stick  others  can  be 
quickly  made  from  the  same  impression  by  the  same  method, 
using  more  care.  With  this  die  and  its  counter-die,  a  piece  of 
ISTo.  29  or  30  gold  plate  is  swaged  to  fit  perfectly  the  cusps  and 
collar,  which,  when  removed,  can  be  held  to  its  place  on  the  cap 
by  the  soldering-clamp,  using  spring  pressure  enough  merely  to 
hold  them  together  for  careful  soldering  with  the  pointed  flame 
so  as  not  to  unsolder  the  collar.  The  seamless  collars  are  excel- 
lent when  care  is  used  in  selecting  the  proper  size,  as  directed 
on  the  diagram  (see  page  223). 

"  The  caps  being  in  place  on  the  cuspid  and  molar,  an  impres- 


DR.  MELOTTE'S  METHOD.  211 

sion  is  taken  with  plaster;  the  caps  accurately  set  in  the  impres- 
sion, and  hard  wax  melted  with  a  hot  spatula  around  the  edges 
of  the  caps.  The  im}>ression  is  then  thoroughly  coated  with 
sandarac  varnish,  after  which  it  is  dipped  for  a  moment  in  water, 
.and  tilled  with  a  wet  mixture  of  one  part  marble-dust  with  two 
parts  of  plaster;  using  great  care  to  perfectly  fill  the  caps  and 
molds  of  the  teeth.  Wait  until  this  mixture  has  become  quite 
hard;  remove  the  cup,  and  Avith  a  suitable  knife  chip  off  the 
plaster  without  marring  the  cast ;    secure  a  good  articulating 

Fig.  444. 


impression,  and  transfer  it  to  the  cast  to  obtain  an  exact  repro- 
duction of  the  relative  occlusions  of  all  the  teeth  involved. 
With  such  an  articulation  in  hand,  and  with  the  means  already 
described  for  swaging  gold  or  platinum  plate  to  fit  the  cusps  and 
articulating  surfiices  of  cither  the  natural  or  artificial  teeth,  it 
should  be  within  the  capacity  of  any  competent  dentist  to  com- 
plete a  suitable  bridge;  although  there  are  practical  ])oints  that 
can  only  be  imparted  by  clinical  instruction  and  actual  demon- 
stration in  the  mouth.  Such  a  bridge  is  shown  in  position  by 
Fiii-.  444." 


CHAPTEE  XII. 


PAETIAL  CAP  AND  PIN-BRIDGE  METHODS. 


Dr.  W.  F.  Litch's  processes  in  this  style  of  work  have  for 
special  cases  many  decided  advantages,  and  are  thus  described 
by  him :  ^ 

"  Fig.  445  represents  a  typical  case,  in  which  a  lateral  incisor 
(crown  and  root)  has  been  lost,  the  cuspid  and  front  incisor,  fully 
vitalized,  and  without  approximal  carious  cavities,  remaining  in 
position. 

"  To  Make  a  Pin  and  Plate  Bridf/e. — 1.  Take  in  plaster  an 
accurate  impression  of  the  cuspid  and  incisor  and  the  interspace. 
From  this  obtain  a  plaster  model  of  the  parts. 

Fig.  445. 


"  2.  Make  from  pure  gold,  rolled  to  the  thinness  of  No.  26^ 
standard  gauge,  base-})lates,  to  be  carefully  adjusted  to  the  palato- 
approximal  surfaces  of  the  cuspid  and  incisor.  These  can  be 
made  by  swaging  on  dies  and  counter-dies  ol)tained  from  the 
model,  but  more  conveniently  l)y  bending  the  gold  into  shape 
upon  the  plaster  model  and  pressing  and  burnishing  it  into  per- 
fect adaptation  upon  the  natural  teeth. 

"  3.  Select  a  plain  plate  porcelain  tooth  of  suitable  length, 
shape,  and  shade,  and  wide  enough  to  fit  easily  into  the  inter- 
space.    Let  the  neck  of  the  tooth  rest  lightly  upon  the  gum. 


^Denial  Cosmos,  vol.  xxviii,  No.  3. 


212 


PARTIAL  CAP  AND  PIN-BRIDGE  METHODS.  213 

"  4,  With  pure  gold  or  i)lutinuiii  makc^  a  Ijackiug  for  the  })0r- 
celain  tooth. 

"  5.  Place  the  tooth  thus  prepared  and  the  base-plates  already' 
made  upon  the  east  and  accurately  adjust  the  approximal  edges 
of  the  l)ase-plates  to  the  backing  of  the  porcelain  tooth  in  situ 
upon  the  cast. 

"  6.  When  this  adjustment  is  made,  cement  together  the  base- 
plates and  backing  with  a  brittle,  resinous  cement  (resin,  two 
parts;  wax,  one  part;  or  sealing-wax  will  answer),  and  l^efore 
the  cement  has  fully  hardened  remove  from  the  cast  to  position 
in  the  mouth,  perfecting  the  final  adjustment  there.  By  this 
method  much  greater  accuracy  of  adaptation  is  obtained,  as  the 
lines  of  length,  width,  and  contour  are  too  fine  to  be  repro- 
duced with  absolute  fidelity  in  a  plaster  model.  In  this  part  of 
the  process  too  much  care  cannot  be  taken  to  have  each  piece  of 
the  appliance  fitted  Avith  absolute  accuracy  to  the  surface  for 
which  it  is  designed.  When  this  has  been  accomplished,  throw 
upon  the  yet  more  or  less  plastic  cement  a  stream  of  ice-cold 
water  from  an  office  syringe ;  this  renders  the  cement  perfectly 
brittle  and  incapaVdc  of  bending.  This  done,  immediately 
remove  from  the  mouth  and  invest  in  a  mixture  of  equal  parts 
of  marble-dust  and  plaster  of  Paris. 

"  7.  After  the  investment  has  firmly  set,  solder  the  base- 
plates to  the  backing,  and  the  backing  to  the  platinum  pins  of 
the  porcelain  tooth,  using  as  a  solder  20-carat  gold.  Thus 
joined,  the  ajipliance  will  present  the  appearance  shown  in  Fig. 
449, — A  representing  the  l)ase-plate  for  the  cus})id;  B,  the  base- 
plate for  the  incisor;  C,  the  porcelain  tooth  with  its  platinum 
backing;  D,  the  points  of  union  between  the  base-plates  and 
backing.  At  these  points  the  greatest  strength  is  required,  and 
it  is  important  that  here  a  large  amount  of  the  solder  should  be 
placed.  The  porcelain  tooth  being  usually  thinner  than  the 
natural  teeth,  there  is  nearly  always  an  angle  or  depression  at 
the  points  indicated,  in  which  the  thickness  of  the  gold  can  be 
considerably  increased  without  interfering  with  occlusion. 

"■  8.  For  the  purpose  of  attaching  the  denture  as  thus  far  con- 
structed, drill  a  small  cylindrical  opening  through  the  palatal 
surface  of   the  enamel  of  the   cuspid  and   incisor  respectively. 


214  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

These  openings  should  usually  be  placed  about  as  indicated  in 
Fig.  448,  at  C,  D.  Sometimes,  owing  to  a  close  occlusion  or  to 
the  contour  of  the  tooth,  it  is  desirable  that  they  should  be  located 
a  trifle  nearer  the  neck  of  the  tooth.  Each  opening  should 
be  well  undercut,  but  must  not  encroach  upon  the  dentine  far 
enough  to  endanger  the  pulp.  In  size  the  openings  need  not 
be  larger  than  will  admit  a  platinum  pin-head,  in  diameter  corre- 
sponding to  E'o.  13,  standard  gauge,  with  a  shank  of  ISTo.  18,  stand- 
ard gauge.  Into  each  of  these  openings  must  be  iitted  a  platinum 
pin  of  the  size  indicated.  The  head  of  each  pin  must  be  made 
thin  and  perfectly  flat  b(^th  upon  its  upper  and  under  surtaces. 

"  9.  In  each  of  the  base-plates  make  an  opening  corresponding 
in  position  to  those  in  the  natural  teeth.  Pass  through  these 
openings  and  cement  in  them  the  free  ends  of  the  platinum  pins. 

Fig.  446.  Pig.  447. 


While  the  cement  is  yet  plastic,  place  the  denture  in  position  in 
the  mouth,  carefully  pressing  the  pin-heads  into  the  openings 
made  for  them,  and  burnishing  the  base-plates  into  perfect 
contact  with  the  palatal  surfaces  of  the  teeth;  chill  the  ce- 
ment, remove  and  invest  as  before,  and  with  20-caratgold  solder 
the  pins  to  the  base-plates,  flowing  upon  them  and  the  backing- 
as  much  of  the  solder  as  may  be  necessary  to  give  them  the 
desired  thickness  and  rigidity ;  the  amount  admissible  largely 
depending  upon  the  nature  of  the  occlusion  ;  a  central  thickness 
of  about  No.  21,  standard  gauge,  being  all  that  is  really  requisite 
for  strength,  while  the  edges  can  be  made  much  thinner. 

"  Fig.  446  represents  the  appliance  without  the  pin.  A  is  the 
porcelain  tooth  and  1)acking;  E,  the  base-plates;  C  and  F,  the 
openings  for  the  pins. 

"  Fig.  447  represents  the  appliance  completed  with  the  pins  in 
position. 


PARTIAL  CAP  AXD  PIX-IiRIDOEMETHODS. 


215 


"Fig.  448  represents  the  natural  teetli  and  interspace  B,  witli 
openings  for  retaining-pins,  C,  D. 

"Fig.  449,  already  described,  represents  the  appearance  pre- 
sented when  the  bridge  is  cemented  in  position. 

"  Jf>  Atiarit  Ihe  Bryhjc. — To  attach  the  bridge  the  best  attaina- 
ble oxyphospliate  cement  should  be  used.  It  is  desirable  that  it 
should  set  slowly.     Thoroughly  dry  the  teeth  and  denture;  mix 


the  cement  to  as  thick  a  consistence  as  is  com[)atible  with  per- 
fect plasticity.  A  thick,  viscid,  semi-fluid  mass  is  what  is 
required.  Witli  suitable  instruments,  swiftly  l)ut  carefully  place 
the  cement  around  the  head  and  sliank  of  each  platinum  pin ,  and 
also  in  the  openings  in  the  natural  teeth.  This  care  is  neces- 
sary in  order  to  exclude  all  air-bubbles  and  thoroughly  engage 
the  pin-heads  in    the   cement.      They  furnish  ample  retaining 


surface,  but  none  to  spare.  In  packing  the  cement  around  the 
pins  the  under  surface  of  the  base-plates  should  at  the  same 
time  be  covered. 

"  The  above  details  being  perfected,  the  denture  is  at  once 
carried  to  position,  and  with  l)road-pointed,  serrated  instruments 
pressed  tirmly  into  })lace,  the  excess  of  cement,  if  of  the  proper 
consistence,  freelv  oozino::  at  all  margins." 


216  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

^'•Application  to  Palpless  Teeth. — In  the  above  description  the 
^itaHty  of  the  pulps  of  the  cuspid  and  incisor  has  been  assumed ; 
but,  as  can  readily  be  understood,  the  pin  and  plate  bridge  can 
be  even  more  readily  and  securely  placed  when  one  or  both 
pulps  are  devitalized,  for  the  reason  that,  the  pulp-chamber  being 
empty,  the  pin-holes  in  that  tooth  can  l)e  made  as  much  larger 
and  deeper  as  may  be  deemed  desirable,  the  size  of  the  pin  being, 
of  course,  correspondingly  increased.  In  a  devitalized  tooth, 
too,  the  base-plates  can  be  sunk  into  the  palatal  surface  when 
they  interfere  with  occlusions,  as  sometimes  happens  when  the 
antagonism  of  the  lower  teeth  is  very  close  and  the  overlap  is 
considerable. 

"  Ordinarily,  however,  such  interference  is  inconsiderable,  and 
the  difficulty  can  always  be  overcome  either  in  devitalized  teeth 
by  the  expedient  just  suggested,  or  by  carrying  the  base-plates 
as  far  away  from  the  cutting-edge  as  practicable,  at  the  same 
time  making  them  at  the  point  of  contact  as  thin  as  is  consist- 
ent with  strength ;  finally,  if  necessary,  removing  a  slight 
portion  of  the  cutting-edge  of  the  occluding  lower  tooth.  .  .  . 

"  As  a  rule  the  writer  has  confined  the  use  of  this  form  of 
bridge  to  cases  in  which  only  a  single  incisor  is  missing,  but  he 
has  successfully  attached  a  front  and  lateral  incisor  to  a  cuspid 
and  the  remaining  front  incisor.  Where  an  unusual  strain 
is  to  be  expected  the  retaining-pins  and  pin-holes  should  when 
practicable  be  made  correspondingly  large,  or  two  smaller  pins 
may  be  anchored  in  one  tooth,  which  latter  plan  gives  very  great 
resisting  power. 

"  Pin  and  Plate  Attachments  to  Bicaspids, — Although  chiefl}- 
applicable  to  the  incisors,  the  pin  and  plate  attachment  may  be 
successfully  comljined  with  crown  or  bar  bridges  for  molars 
and  bicuspids. 

"  Fig.  450  represents  a  practical  case  in  which  tlie  upper  third 
molar  and  tlie  first  bicuspid  (both  without  antagonizing  teeth) 
were  utilized  for  the  attachment  of  a  bridge  made  of  gold 
crowns  with  porcelain  facings,  to  supply  the  loss  of  the  interven- 
ing teeth. 

"  Fig.  451  represents  the  case  as  prepared  for  the  bridge.  A, 
the  inner  cus})  of  the  bicuspid  cut  down  to  allow  the  placing  of 


PARTIAL  CAP  AND  PIN-BRJDQE  METHODS. 


217 


a  sufficiently  thick  crown-plate ;  B,  a  cylindrical  undercut  open- 
ing between  the  cusps  for  a  retain ing-pin;  C,  the  third  molar, 
made  uniform  in  size  from  neck  to  grinding-surfoce,  the  latter 

Fig.  450. 


also  being  considerably  retrenched ;  D,  the  crown-plate  of  a 
partial  cap,  made  of  pure  gold,  soldered  with  20-carat  gold,  and 
so  constructed  as  to  cover  every  portion  of  the  tooth  except  its 

Fig.  451. 


buccal  surface,  the  free  edge  passing  up  under  the  gum  ;  E,  a 

retaining-pin  adapted  to  the  opening  B ;  P,  the  gold  cap  for  the 

molar. 

Fig.  452. 


"  Fig.  452  represents  the  bridge  anchored  in  position  with 
oxyphosphate  cement. 


218 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


"  In  the  above  case  it  will  be  observed  that  there  is  a  con- 
siderable space  between  the  bicuspid  and  cuspid.  This  made  it 
readily  practicable  to  give  so  considerable  a  thickness  to  the 
mesial  wall  of  the  partial  cap  as  to  hold  it  securely  against  the  side 
of  the  tooth.  Had  the  space  been  less,  contact  with  the  cuspid 
would  have  afforded  the  desired  security. 

Fig.  453. 

F 


"  Fig,  453  represents  another  case  in  which  a  bridge  was  at- 
tached by  a  bar,  partial  cap,  and  retaining-pin.  A  is  an  upper 
second  bicuspid  (without  antagonist) ;  B,  its  inner  cusp,  cut  down ; 
C,  opening  for  retaining-pin  ;  D,  second  molar,  with  slot  for  bar; 
E,  cuspid ;  F  represents  the  partial  facing ;  G,  the  retaining-pin  ; 
H,  a  molar  crown  of  gold,  with  porcelain  front;  I,  a  platinum 
bar  attached  to  the  crown  (H)  and  made  to  lit  into  a  slot  (at  D); 

Fig.  454. 


J,  a  plain  plate  cuspid,  heavily  backed  and  strongly  soldered  to 
the  partial  cap,  but  left  without  attachment  to  or  contact  with 
the  cuspid. 

"  Fig,  454  shows  the  bridge  anchored  in  position, 
"  This  case,  after  two  years  of  wear,  is  still  in  perfect  condi- 
tion and  doing  good  service.     As  it  was  possible  to  keep  the 


PARTIAL  CAP  AND  PIN-BRIDGE  METHODS.  219 

gold  attachments,  backings,  etc.,  out  of  sight,  the  ajtpearance 
presented  is  very  natural. 

"  The  absence  of  antagonizing  teeth  for  the  bicuspids  in  each 
of  these  cases  was  a  favorable  condition,  as  a  considerable  thick- 
ness could  1)L'  given  to  the  crown-plate  without  any  interference 
with  occlusion.  When  the  conditions  are  not  so  favorable, 
cutting  down  the  inner  cusp  to  the  required  extent  and  sinking 
the  opening  for  the  retaining-pin  to  the  necessary  depth  are  pro- 
cesses certainly  to  be,  as  a  rule,  preferred  to  the  entire  removal 
of  the  crown  for  the  purpose  of  ferruling  the  root  for  the 
mounting  of  a  crown  of  gold  and  porcelain, — a  procedure,  how- 
ever, not  by  any  means  to  be  indiscriminatelj^  denounced,  for  in 
many  cases  it  is  in  the  highest  degree  advisable. 

"  There  is  this  fact  to  be  considered  in  regard  to  the  use  of  the 
partial  caps  here  figured, — that  many  patients  can  be  induced  to 
consent  to  their  employment  who  would  refuse  to  submit  to 
more  radical  measures,  and  thus,  even  when  the  latter  would  be 
advisable,  the  former  may  be  employed  as  a  compromise,  or  even 
as  a  temporary-  expedient.  Having  once  tested  the  advantage  of 
a  well-fitting  bridge,  the  wearer  is  much  more  likely  to  consent 
to  whatever  measures  are  necessary  to  give  it  security  and  per- 
manence." 


Fig.  455. 
FOR  SHAPIXO  SEA]»1L.£SS  TOOTH-ROOT  COI.L.ARS. 


No.  4. 


Ho.  5. 


No.  6. 


No.  7. 


CHAPTER   XIII. 

THE    MANDREL    SYSTEM. 

In  all  styles  of  collar  crowns  the  shaping  and  adapting  of  the 
collar  is  usually  found  by  many  dentists  to  be  the  most  difficult 
part  in  their  construction.  To  facilitate  its  performance  the 
"  Mandrel  System  "  was  introduced  by  The  S.  S.  White  Dental 
Manufacturing  Co.  The  following  is  a  revised  description  taken 
from  an  article  on  the  subject:^ 

"  An  examination  of  a  large  number  of  human  teeth  shows 
that,  no  matter  how  great  differences  may  exist  in  the  apparent 
shapes  of  the  crowns  of  individual  teeth  of  a  given  class,  there 
is  a  remarkable  uniformity  in  the  configuration  of  their  necks. 
That  is,  the  necks  of  upper  cuspids,  for  instance,  were  found  to 
have  a  fixed  type,  from  which  the  variations  were  very  slight  as 
to  shape,  though  there  appeared  to  be  no  exact  standard  of  size. 
So  of  the  other  classes,  with  the  single  exception  of  the  superior 
molars,  in  which  two  distinct  forms  were  found,  the  first  being 
tliose  in  which  the  buccal  roots  were  wider  than  the  palatal : 
the  second,  those  in  which  the  reverse  condition  was  found,  the 
single  palatal  root  being  wider  at  its  junction  with  the  crown 
than  tlie  two  buccal  roots.  The  occurrence  of  roots  of  the 
second  class  being  rather  exceptional,  the  first  class  was  accepted 
as  the  type. 

"  The  configuration  of  the  necks  of  all  the  teeth  ha\'ing  been 
determined,  a  set  of  mandrels  for  shaping  collars  to  tit  them  was 
devised.  The  set  (Fig.  465)  consists  of  seven  mandrels,  six  of 
which  are  double  end.  Their  shapes  are  modeled  upon  the 
general  typal  forms  of  the  necks  of  the  teeth  which  they  repre- 
sent, and  they  are  made  tapering  to  provide  for  all  required 
variations  in  size.     The  illustrations  are  about  two-thirds  actual 

^Dental  Cosmos,  vol.  xxviii,  No.  8. 

221 


222  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

size,  the  longest  instruments  being  nine  inches  in  length.  The 
cross-sections  show  the  shapes  and  proportionate  sizes  at  the 
greatest  and  least  diameters.  The  long  taper  permits  the  most 
minutely  accurate  adjustment  of  the  collars. 

"  No.  1  is  a  double-end  mandrel,  for  superior  molars,  right  and 
left;  Ko.  2  is  a  single  mandrel,  for  superior  bicuspids,  right -and 
left;  iSTo.  3  is  double-end,  for  superior  cuspids,  right  and  left; 
No.  4,  doable-end,  for  superior  centrals,  right  and  left;  No.  5, 
double-end,  for  inferior  molars,  right  and  left ;  No.  6,  double-end, 
for  the  inferior  centrals,  laterals,  cuspids,  and  first  bicuspids, 
right  and  left;  No.  7,  double-end,  one  end  for  the  superior, 
lateral  incisors,  the  other  for  those  bicuspids  in  which  a  bifur- 
cation of  the  roots,  or  a  tendency  in  that  direction,  extends 
across  the  neck  to  the  crown  in  the  form  of  a  depression  on  one 
or  both  approximal  surfaces.  The  foregoing  scheme  compre- 
hends all  the  teeth  of  the  permanent  set  except  the  second 
inferior  bicuspids.  The  necks  of  these  approximate  those  of 
the  superior  central  incisors  so  closely  in  shape  that  it  was  deemed 
inexpedient  to  make  a  separate  mandrel,  as  the  No.  4  mandrel 
will  serve  for  both. 

"  The  collars  or  bands  are  made  seamless,  of  No.  30  (Ameri- 
can gauge)  gold  plate,  22  carats  fine.  Fifteen  sizes,  each  of 
three  widths  {-^,  -^-^^  and  -^^  inch)  are  made  (Fig.  456),  which  it 
is  believed  will  cover  all  requirements.  These  collars,  although 
devised  as  a  part  of  the  system,  can  be  used  in  all  methods  of 
crown-  and  bridge-work  which  require  bands,  and  possess  many 
advantages  over  any  others.  They  are  really  labor-saving 
de\'ices,  as  their  use  saves  the  time  and  trouble  of  making,  and 
there  is  no  danger  of  their  coming  unsoldered  when  the  pins  or 
the  backing  of  the  crown  is  being  soldered;  and  there  are  no 
hard  spots  to  give  trouble  in  burnishing,  as,  for  instance,  close  to 
the  root,  after  the  collar  has  been  shaped  and  placed  in  position, 
the  whole  surface  being  uniformly  soft. 

"  The  seamless  collars  are  also  especially  adapted  to  removable 
or  detachable  bridge-work.  They  arc  so  constructed  that  Nos. 
1,  16,  and  31  exactly  fit  into  or  telescope  with  Nos.  2,  17,  and  32, 
and  so  on  through  the  entire  set,  each  collar  fits  into  the  series 
next  higher;  so  that  a  root  may  be  banded  with  one  size  and 


TnE  MANDREL  SYSTEM. 
Fig.  4-'>6. 


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224  ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 

the  size  next  larger  used  to  form  the  tube  for  the  telescoping 
crown.  When  desirable,  the  '  seamless  '  collar  can  be  strength- 
ened, after  it  has  been  adapted  to  the  conformation  of  the  crown 
so  as  to  slide  freely  over  it,  by  investing  and  flowing  solder  over 
the  outer  surface ;  or,  still  better,  by  adapting  the  next  larger 
size  of  collar  to  exactly  fit  around  the  first,  and  then  investing 

Fig.  457. 


the  two  and  soldering  them  together.  The  advantages  of  these 
collars  for  this  style  of  work,  and  also  for  the  construction  of 
cap  crowns,  are  ol)vious. 

"  The  other  appliances  specially  devised  for  this  system  are,  a 
reducing-plate  or  contractor,  a  pair  of  collar  pliers,  and  a 
hammer. 

"  The  contractor  (Fig.  457)  contains  holes  which  are  comple- 


THE  MANDREL  SYSTEM. 


225 


muntary  iu  shape  to  the  mandi\'ls.  The  mandrels  being  apphed 
to  the  inner  circumferences  of  the  collars,  while  the  contractor 
must  admit  the  collars  themselves,  the  short  taper  of  the  holes 
in  the  contractor  necessarily  covers  a  somewhat  greater  range  of 


Fig.  458. 


size  than  is  shown  in  the  mandrels.  With  this  appliance  collars 
can  he  evenly  and  accurately  reduced  in  size  at  the  edges,  with- 
out burring  or  buckling.     The  illustration  is  actual  size. 

"  The  collar  pliers  (Fig.  458)  are  for  contouring  the  collars  to 
shape,  one  beak  being  made  convex  and  the  other  concave  to 

16 


226 


ARTIFICIAL  CRO  WN-  AND  BRIDGE-  WORK. 


Fig.  459. 


correspond.  With  this  appliance  the  slightest  changes  required 
in  the  contour  of  the  collars  are  easily  made.  About  a  half-inch 
from  the  extremity  of  the  concave  beak  a  small 
bar  of  flat  steel  is  attached  to  it  by  means  of  a 
screw.  The  free  end  of  the  bar  has  a  minute 
projection  upon  one  face,  the  other  being  rein- 
forced to  flt  into  the  concavity  of  the  beak.  In 
the  center  of  the  face  of  the  convex  beak  is  a 
depression,  into  which  the  projection  on  the 
steel  bar  strikes,  making  a  very  efficient  punch 
for  forming  guards  or  stops  to  prevent  the  col- 
lars from  being  forced  too  far  under  the  gunu 
The  depression  in  the  convex  beak  being 
slightly  larger  than  the  projection  or  punch,  the 
metal  is  not  cut  through,  but  merely  raised  on 
the  side  opposite  to  the  punch.  The  punch 
attachment  being  pivoted  can  be  swung  to  one 
side  when  not  in  use. 

"Fig.  459  is  a  mallet  or  hammer,  with  steel  face 
and  horn  peen.  The  handle  is  nine  inches  long, 
"  One  of  the  appliances  required  is  a  lead 
anvil,  which  being  only  a  piece  of  soft  lead  say 
two  by  tlire^e  inches  and  an  inch  thick  is  not 
illustrated.  The  female  die  of  an  ordinary  case 
will  answer  very  well. 

"  To  illustrate  the  uses  of  these  appliances, 
take  a  case  in  which  the  two  inferior  bicuspids 
of  the  left  side  are  missing,  and  the  crowns 
of  the  cuspid  and  first  molar  so  badly  decayed 
that  the  probabilities  are  that  they  will  soon 
fall  victims  to  the  forceps.  The  old-time  way 
would  have  been  to  extract  the  molar  and  cus- 
pid, and  make  a  partial  plate.  Examination, 
however,  sliows  that  the  roots  of  these  two  teeth 
are  in  good  condition,  aftbrding  an  excellent 
oi)|)ortunity  for  the  construction  of  a  piece  of 
bridge-work. 
"  With  a  corundum-point  or  rotary  file,  cut  ofi'  the  remaining 


THE  MANDREL  SYSTEM  227 

[(ortions  of  tlie  crowns  level  with  the  gum  margins.  Prepare 
the  roors  in  an\^  of  the  well-known  ways,  thoroughly  cleansing 
the  apical  portions  and  filling  them  with  whatever  material  is 
desired,  being  careful  only  that  the  work  is  well  done.  For  the 
better  retention  of  the  filling-material  to  be  placed  in  the  pulp- 
eharnber,  retaining-grooves  can  be  made  or  retaining-posts  in- 
serted. Take  a  piece  of  binding-wire  (No.  26,  American  gauge), 
two  and  one-half  inches  long,  pass  it  around  the  neck  of  the  molar 
stump,  cross  the  free  ends,  and,  holding  the  wire  in  place  with  one 
finger,  twist  the  ends  with  a  pair  of  flat-nose  pliers  until  the  wire 
clasps  the  neck  closely  at  every  point  (Fig.  460).  Where  there  are 
any  irregularities  in  the  contour  of  the  tooth,  it  is  necessary  to 
press  the  wire  into  them  with  an  approximal  burnisher.  It  is 
obvious  that  the  ring  thus  formed  will  show  the  exact  size  and 
shape  of  the  neck  of  the  tooth.     Remov^e  the  ring  carefully,  lay 

Fig.  460.  Fig    461. 


it  on  the  lead  anvil,  put  over  it  a  [)iece  of  flat  metal,  and  with  a 
smart  l)low  from  a  hammer  drive  the  wire  into  the  lead  (Fig. 
461).  Upon  removing  the  wire  an  exact  im|>ression  of  the  ring- 
will  be  left  in  the  lead  anvil.  (This  part  of  the  work,  as  indeed 
all  others,  should  be  done  carefully  as  described.  The  wire  ring- 
may  be  driven  into  the  lead  by  a  direct  blow  of  the  hammer 
face,  but  the  blow  might  not  strike  equally,  and  the  interposition 
of  the  flat  metal  held  level  insures  an  even  impression.  A  piece 
of  an  old  file  is  best,  as  the  file-cuts  keep  the  wire  from  slipping.) 
"Next,  cut  the  wire  ring  at  the  lap,  straighten  out  the  wire, 
and  select  a  suitable  collar  by  comparing  the  length  of  the  wire 
with  the  straight  lines  in  the  diagram  (Fig.  456)  which  show  the 
inside  diameters  of  the  various  sizes.  Should  none  of  these 
correspond  exactly,  take  preferably  the  next  size  smaller.  It  will 
be  i-emembered  that  the  collars  are  Xo.  30  in  thickness,  while 


228 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


Fig.  462. 


the  wire  with  which  the  conformation  is  secnred  is  No.  26.  This 
difference  permits  the  collar  when  contoured  to  shape  to  enter 
the  lead  impression  readily,  a  decided  advantage  in  fitting. 
Having  selected  the  collar,  fit  it  to  mandrel  No.  5,  with  the  peen 
of  the  hammer,  holding  it   upon  the  lead  anvil,  and  using  a 

slight  pushing  force  to  help  in 
stretching  and  forming  it  (Fig. 
462).  Having  driven  the  collar  to 
form,  remove  it  from  the  mandrel 
and  try  in  the  lead  impression. 
If  it  does  not  fit  exactly,  return 
it  to  the  mandrel  and  stretch  it  a 
little,  when  it  will  usually  fit  per- 
fectly, as  the  mandrels  have  been 
designed  carefully  to  the  average 
shapes  which  obtain  in  the  great 
majorit}-  of  tooth-necks.  In  the 
exceptional  cases  where  the  collar 
does  not  fit  it  can  be  readily  con- 
toured to  the  exact  shape  with  a 
pair  of  flat-nose  pliers.  Of  course,  if  it  fits  the  impression  in 
the  lead,  it  will  fit  the  neck  of  the  tooth,  always  provided  the 
measurement  and  the  impression  have  been  carefully  made. 

'•'■  If  the  collar  or  band  has  been  accidentally  stretched  too 
much,  or  if  for  any  reason  when  brought  to  shape  it  is  too 
large,  its  root  end  can  easily  be  reduced  to  the  proper  size  by 


Fig.  463. 


Fig,  464. 


m 


the  use  of  the  contractor.  Place  the  edge  of  the  collar  which 
is  to  fit  the  root  in  the  proper  hole ;  hold  it  level  with  a  piece  of 
file  as  in  taking  the  lead  impression  of  the  ring,  and  tapping 
lightly  on  the  file  drive  the  collar  into  the  plate  (Fig.  463)  until 
the  proper  reduction  is  made.  The  collar  is  next  '  festooned ' 
to  correspond  to  the  shape  of  the  maxillary  ridge.     Lay  it,  gum 


THE  MANDREL  SYSTEM. 


229 


edge  up,  on  the  lead  anvil,  and  with  the  piece  of  flat  tile  ;;nd 
the  hammer  drive  it  into  tlie  lead.  A  feAv  cuts  with  a  fine  half- 
round  tile  across  the  approximal  diameter  will  conform  ihe 
edges  to  the  surface  of  the  ridge  (Fig.  4(34).  Then  place  the 
collar  in  position,  and,  having  ascertained  just  how  far  it  should 
go  dow  II  on  the  root,  remove  it,  and  with  the  small  spring  punch 
in  the  collar  pliers  form  projections  on  the  inside  of  the  band  at 
the  proper  points  to  serve  as  stops,  which,  resting  on  the  top  of 
the  root,  will  prevent  the  collar  from  being  forced  farther  down 
upon  it  than  is  desirable  (Fig.  4(35). 

"  A  collar  for  the  cuspid  is  then  iitted  in  the  same  manner, 
using  mandrel  Xo.  (3  for  shaping,  after  which  the  case  is  ready 
for  the  building  of  the  bridge. 

Fig.  4G5.  Fig.  4G6. 


I  V 


"  Cement  with  oxyphosphate  both  collars  in  position.  Then 
take  an  impression  of  the  parts,  including  the  interiors  of  the 
excavated  pulp-chambers,  from  which  make  a  cast  in  the  usual 
way.  Bend  a  short  piece  of  half-roujid  gold  or  platinum  w  ire 
into  the  form  of  a  horse-shoe,  the  two  extremities  of  wliich 
shall  tit  into  tlie  roots  of  the  molar.  Then  take  a  longer  piece 
of  the  same  wire,  somewhat  more  than  enough  to  extend  from 
the  toe  of  the  horse-shoe  when  in  position  to  the  cuspid  root ; 
bend  one  end  of  it  at  a  right  angle,  or  nearly  so,  to  flit  the  root 
of  the  cuspid,  and  (cutting  ofl:'  any  excess  of  length)  solder  the 
other  end  to  the  toe  of  the  horse-shoe.  The  bar  extending 
between  the  two  roots  is  the  truss  of  the  bridge.  Next,  place 
the  appliance  on  the  cast  (Fig,  466),  holding  it  in  position  with 


230  ARTIFICIAL  GROWN-  AND  BRIDGE- WORK. 

wax,  and  select  the  teeth  to  take  the  place  of  the  missing- 
bicuspids  and  molar.  The  best  form  for  this  purpose  is  a  tooth 
havino;  holes  extendino*  throus-h  it  vertically  from  the  neck  to 
the  grinding-surface  similar  to  the  well-known  Bonwill  crown. 

"  The  crowns  used  should  be  large  enough  to  fill  the  space 
rather  tightly,  even  if  their  sides  have  to  be  flattened  slightly  to 
let  them  in.  If  the  teeth  do  not  fill  the  space  tightly,  a  small 
portion  of  plastic  filling-material  crowded  between  them,  as 
mortar  between  the  granite  blocks  in  the  arch  of  a  railway 
bridge,  will  greatly  increase  the  strength  of  the  work. 

"  After  the  teeth  are  ground  to  fit  and  the  proper  length  for 
occlusion  is  ascertained,  the  truss  is  covered  "svith  a  thin  film  of 
wax,  upon  which  the  crowns  are  again  pressed  to  their  positions. 
Upon  the  removal  of  the  crowns  the  impression  of  the  holes 
running  through  them  will  be  found  in  the  wax.  At  these 
points  drill  holes  through  the  bar  with  a  small  twist-drill  run  by 
the  engine,  and  into  these  fit  and  solder  the  pins  for  the  support 
of  the  crowns. 

"  The  bridge  is  now  ready  to  be  attached  permanently.  Set 
the  crowns  in  position  upon  their  supporting  pins  to  secure  the 
proper  alignment.  (If  the  operation  were  upon  the  upper  jaw 
the}'  would  have  to  be  held  with  wax.)  Put  into  the  canals  of 
the  supporting  roots  (the  cuspid  and  first  molar)  a  suflicicnt 
quantity  of  some  quick-setting  plastic,  as  oxyphosphate,  to  about 
half  fill  the  pulp-chamber,  but  not  enough  to  prevent  the  sup- 
ports of  the  truss  from  being  forced  home.  Force  the  bridge 
supports  to  place,  and  after  allowing  the  filling-material  to  become 
set  remove'the  crowns.  Fill  the  remainder  of  the  pulp-chamber 
and  the  whole  of  the  collar  with  gold  or  with  amalgam,  gutta- 
percha, oxyphosphate,  or  any  suitable  plastic  (Fig.  467).  Set 
the  crowns  permanently,  the  molar  and  cuspid  first,  as  this 
afifords  greater  facility  for  the  trimming  off  of  any  excess  of  the 
filling-material  used  in  the  attachment.  For  attachment  of  the 
crowns,  gutta-percha  is  probably  the  best  material,  as  crowns 
set  with  it  are  readily  removed  for  the  correction  of  any  in- 
accuracies of  occlusion  or  alignment,  by  grasping  them  between 
the  beaks,  previously  warmed,  of  a  pair  of  universal  lower 
molar  forceps.     The  heat  warms  the  gutta-percha  and  releases 


THE  MANDREL  SFSTE.^L 


231 


the  tooth,  ^vllich  can  then  be  re-set  properly.  In  attacliing 
crowns  with  gutta-percha  the  holes  in  the  crowns  are  first  filled 
with  the  material,  after  which  the  crown  is  warmed  and  forced 
to  place.     Any  of  the  other  plastics  ordinarily  used  in  setting 


Fro.  467. 


Bonwill    crowns    can    he    employed,  at   the    discretion    of    the 
operator.     Fig.  468  shows  the  case  completed. 

''  In  securing  the  occlusion  of  a  piece  of  bridge-work  it  is  well 
to  make  the  artificial  teeth  a  little  short,  so  that  the  natural  teeth 
on  both  sides  will  meet  the  first  shock  of  mastication.  Xature 
will  correct  the  occlusion  in  time  by  slightly  elongating  the 
roots  supporting  the  In-idge.  If  the  artificial  crowns  are  per- 
mitted to  strike  the  natural  teetli  from  tlie  first,  the  undue  strain 

Fig.  4G8. 


upon  the  two  supporting  I'oots  may  cans*.'  soreness  and  perhaps 
more  serious  consequences. 

"  When  a  sound  tooth  is  to  be  used  as  one  of  the  supports  of 
the  bridge,  a  modification  of  the  method  just  described  is 
necessary.  Take  a  case  where  it  is  desired  to  bridge  the  space 
caused    by  the   loss  of   the   right  inferior   l)icuspids   and   first 


232 


ARTIFICIAL  CROWN-  AND  BRIDGE- WORK. 


molar.  The  crown  of  the  right  cuspid  is  nearly  gone,  but  the 
root  is  sound  and  capable  of  supporting  one  end  of  the  bridge. 
The  other  end  will  be  attached  to  the  second  molar,  which  is 
a  sound  tooth.  Prepare  and  band  the  cuspid  root  as  before ; 
dress  off  the  second  molar  crown  until  it  is  slightly  smaller  than 
the  neck,  and  shorter  at  the  occluding  surface,  so  as  to  permit 
a  cap  to  be  telescoped  over  it,  and  take  the  measure  of  the 
crown  with  the  binding-wire.  Select  a  suitable  seamless  collar 
of  sufficient  width  to  extend  from  the  neck  to  a  little  beyond  the 
grinding-surface,  and  drive  it  up  on  the  proper  mandrel  to  get 
the  general  shape,  but  not  the  full  size  required  to  fit  the  tooth, 
leaving  it  so  that  the  edge  having  the  larger  circumference  will 
just  pass  over  the  end  of  the  crown ;  place  the  collar  on  the 
tooth,  and  with  a  block  of  wood  and  the  mallet  tap  it  to  place 

Fig.  469. 


just  l)eyon(l  the  free  margin  of  the  gum.  This  method  will 
make  a  close  fit,  as  the  collar  will  readily  stretch  all  that  is 
necessary.  With  a  sharp-pointed  instrument  mark  the  length 
of  the  crown  and  line  of  the  gum  margin,  remove  the  collar, 
and  cut  it  to  the  proper  form  as  indicated.  Then  in  a  piece  of 
gold  plate  of  the  thickness  used  for  caps  form  four  little  depres- 
sions of  the  general  character  of  an  impression  of  the  molar 
cusps.  An  easy  way  to  do  this  is  to  lay  the  plate  on  the  lead 
anvil ;  then  with  the  ball  on  the  end  of  an  ordinary  socket- 
handle  and  the  hammer  the  depressions  are  made  in  a  moment. 
Clamp  the  collar  on  the  })late,  borax  it,  charge  with  solder,  and 
heat  till  the  solder  fiows.  Cut  off  the  surplus  plate,  and  a  per- 
fect cap  for  the  molar  is  made.  Place  it  on  the  tooth  and  take 
an  impression,  and  thereafter  proceed  as  before  directed  to  make 


DETACHABLE  BRIDGE-  WORK. 


235 


the  truss  of  the  bridge  and  mount  the  teeth,  except  tliat  in  this 
case  the  posterior  end  of  the  truss  is  to  be  sohk'red  to  tlie  molar 
cap.  For  the  final  attachment  place  a  little  oxyphosphate  in  the 
cap  to  secure  it  lirmly  (Fig.  469),  lirst  cutting  a  slot  in  the  crown 
end  of  the  cap  for  the  escape  of  the  excess  of  material.  Pressure 
upon  the  filling-material  hastens  its  hardening."  .     .    . 

DETACHABLE   BRIDGE-WORK. 

"  A  method  of  constructing  a  detachable  bridge  applicable 
to  cases  where  one  or  both  of  the  supports  or  piers  are  sound 
teeth  is  as  follows:  In  the  case  adduced  for  illustration  the 
right  inferior  cus})id  crown  was  decayed,  and  both  of  the  bicus- 
pids and  the  first  molar  were  absent.  The  supports  for  the 
bridge  were  the  sound  second  molar  and  the  cuspid  root.  After 
the  cus})i(l   root  was   [irepared  and   banded,  the   crown   of  the 

Fig.  470. 


molar  was  reduced  very  slightly, — not  sufficient  to  destroy  the 
enamel,  but  just  enough  to  permit  a  collar  })roperly  fitted  to  pass 
over  it.  A  collar  somewhat  wider  than  the  lenerth  of  the  crown 
from  grinding-surface  to  neck  was  fitted  and  cut  to  the  prosier 
width.  Two  lugs  were  then  soldered  upon  the  anterior  and 
posterior  sides  and  l)ent  to  fit  into  the  ap})roximal  fissures,  which 
were  slightly  cut  out  to  admit  them.  An  impression  was  taken, 
the  collar  coming  away  in  the  plaster,  and  a  cast  was  made  with 
the  collar  in  position.  A  coned  tube  ^^■as  then  made  for  the 
root  of  the  cus[)id  and  a  coned  pin  fitted  into  it.  A  truss  of 
half-round  wire  was  made,  to  which  the  coned  pin  and  the  molar 
collar  were  soldered  (Fig,  470).  A  half-clasp  to  grasp  the  lateral 
was  next  soldered  to  the  end  of  the  ti'uss  to  be  supported  by  the 


234 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


cuspid.  The  object  of  this  clasp  was  to  guard  against  the  teeth 
being  thrown  out  of  proper  alignment  by  the  force  of  mastica- 
tion. Bonwill  crowns  were  then  vulcanized  to  the  truss,  after 
their  supporting  pins  had  been  titted  and  soldered  to  it.  (Counter- 
sunk crowns  can  be  used  as  well  in  the  same  way.  Plain  plate 
teeth  may  also  be  used  in  this  style  of  work,  in  which  event  they 
are  to  be  soldered  to  the  truss.)  The  bridge  was  then  ready  to 
be  set,  which  was  accomplished  in  the  following  manner :  The 
cuspid  root  was  nearly  tilled  with  oxyphosphate,  and  the  coned 
tube  was  placed  upon  the  pin.  The  band  was  put  on  the  molar, 
and  the  coned  pin  with  the  tube  upon  it  was  forced  into  the 
plastic  in  the  cuspid.  As  soon  as  this  became  set,  the  tube  was 
held  permanently,  while  the  bridge  itself  could  be  removed  when- 
ever desired  (Fig.  471). 

Fig.  471. 


"  This  method  of  fixing  the  tube  allows  considerable  range  in 
its  adjustmerlt.  In  soldering  the  coned  pin  to  the  truss,  care 
should  be  taken  to  set  it  at  an  angle  exactly  parallel  to  the  axis 
of  the  molar;  otherwise  there  will  be  difficulty  in  removing  the 
bridge. 

"  A  second  style  of  detachable  bridge-work  to  be  described 
involves  the  use  of  cusp  crowns  (Fig.  472)  for  supporting  posts 
or  piers.  Suppose  a  case  where  a  bridge  is  required  to  extend  from 
the  right  inferior  cuspid  to  the  right  inferior  second  molar,  with 
only  the  roots  of  the  two  teeth  named  as  supports.  Prepare  the 
roots  and  pulp-chambers.  Set  screw-posts  into  the  dentine  for 
anchorage  or  as  retaining-pins,  and  fit  the  collars,  using  sizes  wide 
enough  to  form  the  walls  of  the  crowns.  Fill  the  pulp-chamber 
and  cement  on  the  collars,  filling  about  two-thirds  of  the  depth  of 


DETACHABLE  BRIDGE-WORK. 


235 


the  collars  with  a  plastic  filling-material,  packing  it  well  around 
the  retaining-posts.  Select  suitable  cusp  crowns  for  the  molar 
and  cuspid,  and  place  them  in  the  ends  of  the  bands  to  ascertain 
the  occlusion.  If  too  long,  shorten  the  cusps  or  reduce  the 
bands  with  engine  corundums  or  rotary  files,  and  when  the 
correct  articulation  is  found  form  a  small  square  shoulder  in  the 
lingual  edge  of  the  cuspid  and  in  the  posterior  grinding-surface 
of  the  molar.  Fill  the  remaining  portion  of  the  collars  with 
plastic  mixed  somewhat  thinner  than  the  first  lot,  and  set  the 
cusp  crowms  in  position.  If  there  are  antagonizing  teeth  the 
mere  closing  of  the  patient's  jaws  will  force  the  crowns  to  place. 
If  there  are  no  antagonizing  teeth  tlie  crowns  can  be  readilj- 
tapped  to  place  with  the  mallet,  using  a  piece  of  wood  as  a 
driver.  Allow  the  filling-material  to  set  firmly,  trimming  off 
any  excess  which  mav  exude  around  the  collars. 


''  Bridge  supports  or  piers  constructed  on  this  plan  are  strong 
and  durable,  and  likely  to  withstand  any  strain.  Take  an 
impression,  and  proceed  to  fit  seamless  collars  to  telescope  over 
those  already  set  upon  the  cuspid  and  second  molar  roots.  It 
will  be  rememl)ered  that  these  collars  are  so  made  that  each  size 
telescopes  into  the  next  higher  series.  If  the  proper  sizes  are 
selected  for  the  outside  or  female  bands,  the  work  of  fitting  is 
readily  and  quickly  accom}tlished,  forming  tubes  which  slide 
easil}'  over  the  supporting  piers,  and  at  the  same  time  fit  closelj'. 
It  is  only  necessary  to  take  care  in  shaping  the  tubes  not  to  drive 
them  too  far  up  on  the  mandrels  and  thus  stretch  them  so  as  to 
destroy  the  fit.  To  the  outer  end  of  each  of  the  tubes  solder  a 
small  piece  of  gold  plate,  forming  partial  caps  so  placed  as  to 
rest  when  in  position  upon  the  shoulders  previously  cut  in  the 
cusp  crowns.  Adjust  a  truss  bar  of  half-round  gold  wire,  to  the 
ends  of  which  solder  the  tubes.     The  truss  is  now  readv  for  the 


236 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


teeth,  which  may  be  of  any  of  the  forms  used  for  this  purpose, 
and  the}^  may  be  attached  to  the  bar  in  any  way  desired.  One 
of  the  strongest  attachments  is  vulcanite.  Fig.  473  shows  the 
construction  and  the  finished  case. 


Fig.  473. 


"  A.n  easy  moditicatiou  of  the  plan  just  described  is  readily 
adapted  to  cases  where  only  a  small  space  is  to  be  filled  and  one 
end  of  the  bridge  is  to  be  supported  by  a  sound  tooth.  Thus, 
suppose  it  is  desired  to  bridge  a  space  formerly  occupied  by  the 
two  inferior  left  bicuspids,  the  crown  of  the  first  molar  being  a 
mere  shell.     The  operation  would  be  essentially  the  same  as  in 


Fig.  474. 


Fig.  475. 


the  previous  case,  except  that  the  sound  cuspid  would  be  utilized 
for  one  of  the  piers  as  follows :  Fit  a  seamless  collar,  cut  out  a 
portion  of  it  so  that  it  will  embrace  only  about  two-thirds  of  the 
cuspid  crown,  and  solder  a  partial  cap  or  cover  to  it,  as  illustrated 


DETA  CHA BLE  BRIDGE-  WORK.  237 

in  Fig.  474.  Or,  if  deemed  preferahle,  the  cuspid  may  be  separ- 
ated from  the  lateral  incisor  with  the  corundum-disk  and  the 
collar  allowed  to  embrace  the  whole  crown. 

"  A  crown  broken  from  a  bridgt  constructed  by  any  of  the 
methods  above  described  can  be  easily  substituted,  and  the  piece 
when    repaired   will    be   as   strong   and    serviceable    as   it  was 

orio'inall}'. 

Fig    470. 


"  It  has  not  been  deemed  necessary  to  detail  the  construction 
of  a  single  crown  separately,  as  all  the  steps  are  included  in  the 
building  of  bridges,  which  have  been  described  minutely.  Por- 
celain cusps  of  the  general  form  illustrated  in  Fig.  475  have  been 
designed  specially  for  these  cases.  In  mounting  them  the  gold 
band  is  cut  away  on  the  buccal  side  as  shown  in  Fig.  476  to 
permit  the  porcelain  to  show." 


CHAPTER    XIV. 

PORCELAIN   BRIDGE-WORK. 

For  an  ideal  piece  of  bridge-work  that  will  dispense  with  the 
objectionable  features  of  a  permanently  attached  bridge  and 
refute  the  most  forcible  arguments  against  the  system,  porcelain 
is  the  most  suitable  material  known. 

DR.    BROWN'S    METHOD. 

Dr.  E.  Parmly  Brown,  of  Flushing,  N.  Y.,  has  invented  and 
introduced  a  method  of  porcelain  and  iridio-platinum  bridge- 
work,  which  possesses  special  merit. 

The  advantages  claimed  for  it  as  a  method  of  bridge-work  are 
as  follows  : 

It  is  formed  entirely  of  porcelain  with  an  iridio-platinum  bar 
running  through  the  denture  as  a  sustaining  shaft,  thus  present- 
ing a  perfect  continuity  of  porcelain  surface. 

It  is  unaffected  by  any  chemical  action  or  condition  in  the 
mouth.  It  has  no  so-called  self-cleansing  spaces,  because  none 
are  required. 

A  benign  and  natural  form  of  contour  is  presented  on  its 
palatal  surface,  as  the  base  of  each  tooth  presses  tightly  onto  the 
membranes  of  the  gum,  which  closes  or  hugs  closely  around  it. 

And  lastly,  it  has  the  merit  of  simplicity  of  construction  in 
comparison  with  the  other  methods  in  practice. 

Construct iov. — The  bridge  is  formed  by  spanning  intervening 
spaces  between  certain  natural  teeth  or  roots  with  artificial 
porcelain  substitutes  baked  onto  an  iridio-platinum  bar;  either  or 
both  ends  of  the  bar  being  anchored  in  a  crown,  or  in  a  filling 
inserted  in  the  approximal  portion  of  the  adjoining  tooth.  The 
■roots  to  be  crowned  and  used  as  foundations  for  the  bridge  are 
prepared  as  for  single  crowns.  If  the  end  of  the  bar  is  to  be 
238 


PORCELAIN  BRIDGE-  WORK.  289 

Hxed  in  a  natural  tooth,  the  cavity  that  is  to  receive  and  anchor 
it  is  opened  up  sufficient  to  admit  it, — in  the  bicuspids  and  mo- 
lars from  the  grinding-surface  to  the  cervico-approximal  edge, 
and  in  the  incisors,  on  the  approximal  side,  with  an  opening  on 
the  palatal  or  labial  face,  as  indicated.  A  square  bar  of  iridio- 
platinum  wire  from  ^o.  13  to  Xo.  15,  U.  S.  standard  gauge,  in 
thickness,  is  fitted  either  to  the  cavities  of  the  teeth  in  which  it  is 
to  be  anchored,  or  bent  and  fitted  in  any  devitalized  tooth  or  root 
which  is  to  act  as  an  abutment.  The  end  of  the  wire  that  forms 
the  post  is  pointed  and  introduced  well  up  the  root-canal,  and 
the  end  forming  the  bar  is  slightly  flattened  or  squared.  Any 
intervening  root-posts  are  fitted  and  riveted  to  the  bar  as  it 
passes  above  them. 

To  this  bar  the  teeth  used,  which  are  ordinary  Fio.  477. 
plate  teeth,^  are  fastened :  incisors  by  slightly 
flattening  the  bar  and  riveting  them  fiist,  or  when 
straight-pin  teeth  are  used  by  bending  the  pins 
over  the  bar  (Fig.  477) ;  bicuspids  and  molars  with 
straight  pins,  by  grinding  a  slot  with  a  disk  l)e- 
tween  the  pins  and  bending  them  over  the  bar,  which  is  slightly 
barbed  and  set  in  the  slot. 

The  proper  position  of  each  tooth  having  been  determined  by 
adjustment  in  the  mouth,  or  to  the  articulating  model,  the  rivets 
and  bar  on  each  tootli  are  carefully  filled  around  and  the  cervico- 
palatal  portion  rounded  ofl"  with  porcelain  body  so  as  to  present 
a  natural  surface  to  the  tongue.  The  shape  of  the  end  of  the 
root  is  given  to  the  crown  by  placing  the  porcelain  body,  to 
which  a  small  quantity  of  starch  has  been  added,  around  the 
post  as  it  is  fixed  in  position  on  the  model;  the  plaster  having 
been  previously  varnished  with  collodion  to  prevent  cohesion. 
The  spaces  between  the  teeth  on  the  line  of  the  bar  are  to  be 
substantially  joined  with  the  porcelain  body;  free  spaces  between 
the  teeth  at  the  cervical  portion  are  to  be  preserved  as  much  as 
possible  without  interfering  with  strength  or  producing  places 
that  will  be  uncleanh*. 

1  Dr.  Brown  uses  The  8.  6.  White  Dental  Mfg.  Co.'s  teeth  entirely  forthis  work, 
as  he  has  found  them  the  most  suitable,  being  the  only  kind  that  will  retain  their 
color  in  the  intense  heat  to  which  they  are  suhjecied. 


240 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


The  bridge  is  then  placed  on  a  slide  in  the  muffle  of  a  con- 
tinuous-gum furnace,  being  sustained  in  position  bv  inserting 
the  pins  in  holes  drilled  in  the  side  (Fig.  478)  or  by  suspending 
it  with  platinum  wirebetwef  n  two  platinum  posts  inserted  in  the' 
slab,  and  then  baked  the  same  as  for  con  tinuous-gum  work.  The 
brido:e  is  next  fitted  to  the  mouth.  If  any  alterations  are  re- 
quired they  should  be  made,  or  if  any  imperfections  in  the  body 
occur  the  places  should  be  filled  in  and  the  bridge  again  baked. 
It  is  then  ready  for  insertion. 

Insertion. — When  the  bridge  is  supported  by  crowns  alone,  the 
posts  are  barbed  and  the  bridge  is  then  cemented  on,  the  same 
as  any  other.  If  one  end  is  supported  on  a  crown  and  the 
other  by  a  bar,  the  filling  on  the  bar  end  is  inserted  up  to  the 

Fig.  478. 


position  the  bar  is  to  occupy  before  fastening  the  pin  of  the  crown 
end,  which  is  then  cemented  and  the  filling  of  the  bar  end  com- 
pleted. If  both  ends  are  bars,  both  fillings  are  inserted  up  to 
the  position  of  the  bars,  the  bridge  inserted,  and  the  fillings 
finished;  the  bridge  being  held  by  an  instrument  or  the  fingers 
until  the  bar  ends  are  partly  covered. 

When  gold  is  used,  the  rul)ber-dam  should  first  be  applied, 
and  the  cervical  portion  of  the  teeth  of  the  bridge  pressed 
tightly  into  it  to  avoid  any  space  being  left  after  its  removal  and 
the  completion  of  the  operation. 

When  amalgam  is  used,  the  rubber-dam  is  not  necessary. 

In  Fig.  479,  No.  1  is  a  third  molar,  pulp  alive,  with  large 
filling;  No.  2  is  a  porcelain  bridge;  No.  3  is  a  first  molar,  pulp 
dead,  with  a  metal  bar  entering  the  pulp-chamber. 


PORCELAIN  BRIDGE-  WORK. 


241 


111  Fig.  480,  N'o.  1  is  a  second  molar,  pulp  alive,  with  a  crown 
filling  of  gold  or  amalgam  retaining  the  bar;  No.  2  is  a  porce- 
lain bridge;  No.  3  is  a  gold  crown  with  bar  passing  through 
one  side  of  the  crown  into  the  root. 

Fig.  481  is  a  view  of  a  bridge  of  two  teeth, — a  central  porce- 


FiG.  479. 


Fig.  480. 


Fig.  481. 


lain  crown  with  a  lateral  baked  onto  it,  the  bar  and  pin  being  of 
the  same  piece,  bent  at  al)out  a  right  angle. 

In  Fig.  481,  No.  1  is  a  porcelain  crown  forming  part  of  the 
bridge;  No.  2  a  bridged  lateral  with  metal  bar  baked  through 
it;  No.  3  a  living  cuspid  with  a  metal  bar  running  into  the 
center  of  a  solid  gold  filling. 


Fig.  482. 


Fig.  484. 


Fig.  483. 


Fig.  482  is  a  view  of  a  central  incisor  bridged  onto  two  teeth 
whose  pulps  have  been  lost. 

Fig.  483  is  a  view  of  the  attachment  of  the  bridge  to  a  natural 
or  artificial  crown  standing  alone.     The  bar  can  be  anchored  in 

16 


242 


ARTIFICIAL  CROWN-  AND  BRIDGE- WORK. 


a  filling  in  the  natural  crown  or  attached  to  the  artificial  one. 
ISTos.  1  and  3  are  teeth  on  a  porcelain  bridge ;  i^o.  2  the  natural 
tooth  or  artificial  crown  on  which  the  bridge  is  saddled. 

Figs.  484,  485,  and  486   represent  a  bridge  of  eleven  teeth 


Fig.  485. 


Fig.  486. 


recently  inserted  by  Dr.  Brown  on  two  cuspid  roots,  a  pulpless 
molar  on  the  left  side  which  was  capped  with  a  gold  crown, 


Fig.  487, 


through  the  side  of  which  the  bar  was  passed  and  anchored  in 
the  root,  and  a  molar  on  the  right  side  into  which  the  other  end 
of  the  bar  was  anchored  in  a  gold  filling. 

Fig.  487  represents  a  bicuspid  bar-bridge  anchored  in  the  molar 


PORCELAIN  BRIDGE-WORK. 


248 


and  first  bicuspid.  Tiie  side  cut  shows  the  construction.  This 
operation  was  performed  by  Dr.  Brown  for  Dr.  Crenshaw,  of 
Atlanta,  Georgia,  at  the  anniversary  clinic  of  the  First  District 
Dental  Society  of  the  State  of  New  York,  in  January,  1887. 

Fig.  488  represents  an  extension  bridge  in  which  the  abut- 
ment consists  of  a  crown  and  bar  combined. 

Fig.  489  represents  an  extension  ])ar-bridge.     The  filling  in 


Fig.  488. 


Fig.  489. 


'^\^  ^' 


the  second  bicuspid,  which  extended  from  the  mesial  to  the 
distal  side,  had  been  inserted  some  time  previously.  Enough  of 
the  gold  was  removed  from  the  mesial  section  of  the  filling  to 
admit  the  bar,  which  was  then  securely  anchored  and  the  filling 
I'cstored  to  its  original  form.     The  operation  was  performed  by 

Fig.  490. 


Dr.  l>rown  for  Dr.  F.  P.  Hamlet,  and  to  present  date  has  been 
worn  two  years.  The  antagonizing  teeth  in  the  act  of  occlusion 
favor  the  artificial  tooth  forming  the  bridge. 

In  porcelain  bridge-work,  should  a  case  require  it,  artificial 
o-um  in  a  moderate  amount  can  be  formed  above  the  teeth  of 


244 


ARTIFICIAL  CROWN-  AND  BRIDGE-WORK. 


the  bridge,  to  restore  the  contour  of  the  parts.  Figs.  490  and 
491  ilkistrate  a  case  of  this  character.  A,  Fig.  492,  shows  the 
labial  and  B  the  Ungual  aspect  of  the  incisor  bridge  before 
insertion. 


Fig.  491. 


Fig.  492. 


In  forming  this  style  of  porcelain  bridge,  when  it  is  considered 
preferable  to  cap  the  roots,  platinum  plate  can  be  struck  up  for 
the  purpose  as  described  at  page  100,  and  after  lieing  adjusted 

Fig.  493. 


to  the  ends  of  the  roots  the  posts  are  passed  through  them,  as 
illustrated  in  Fig.  493.  Cap  and  bar  are  then  soldered  together 
with  a  very  small  quantity  of  pure  gold,  and  the  construction  of 


the  bridge  continued. 


PORCELAIN  BRIDGE- WORK. 


245 


Fig.  494  represents  a  case  recently  restored  \)\  Dr.  Brown's 
method  by  Dr.  M.  L.  Rhein,  of  IS'ew  York.  To  remedy  the 
abnormal  character  of  the  occlusion,  the  lower  anterior  teeth 
and  the  right  upper  cuspid  were  trimmed  to  the  dotted  line  seen 
in  the  figure.  To  replace  the  missing  teeth  porcelain  bridge- 
work  was  then  constructed.     Tlie  lateral  and  central  roots,  and 

Fio.  494. 


the  right  cuspid  and  the  molar,  constituted  the  abutments.  On  the 
central  and  lateral  roots  were  mounted  caps  with  collars.  A 
platinum  crown  was  then  made  for  the  cuspid  (Fig.  495),  and  to 
this  crown  was  attached  the  bar,  which  was  extended  to  its 
anchorages  in  the  molar  crown  and  the  lateral  and  central  roots, 
the  caps  on  the  ends  of  which  the  posts  pierced.  Owing  to  the 
large  (piantity  of  porcelain  body  to  be  used  in  forming  the  artificial 


Fig.  495. 


Fig.  496. 


gum,  a  strip  of  platinum  plate  was  extended  aliove  the  bar  to 
stiffen  its  projecting  ends  and  prevent  warpage  in  baking.  The 
artificial  teeth  were  then  articulated  to  meet  the  incisive  edges  of 
the  inferior  natural  teeth,  and  thus  in  a  measure  overcome  the 
deformity  caused  by  the  abnormal  occlusion.  In  doing  this  the 
labial  aspect  of  the  cuspid  was  covered  by  the  artificial  teeth.  Por- 
celain gum  was  then  formed  above  the  teeth  to  restore  the  contour 


246 


ARTIFICIAL  CROWN-  AND  BRIDGE- WORK. 


of  the  parts.  Fig.  496  shows  the  finished  bridge.  In  Fig.  497 
the  bridge  is  seen  in  position.  The  artistic  result  and  improved 
appearance  effected  are  at  once  apparent.  The  mechanical  con- 
struction of  the  piece  was  intrusted  to  Dr.  C.  L.  Andrews. 

Dr.  Brown's  system  and  method  of  bridge-work  compares 
with  other  forms  of  bridge-work  as  continuous-gum  work  com- 
pares with  other  forms  of  plate-work.     Its  cleanliness,  through 

Fig.  497. 


the  unalterable  character  and  continuity  of  its  surface  and  the 
incorruptibility  of  the  material,  renders  it  a  superior  form  of 
denture. 

The  ultimate  value  of  this  method,  however,  as  a  means  of 
replacing  lost  members  of  the  dental  arch,  depends,  like  others, 
on  its  proper,  correct,  and  skillful  application  to  cases  suitable 
for  it.  . 


PAET   lY. 

MATERIALS  AND  PROCESSES  USED  IN  CROWN-  AND 
BRIDGE-WORK. 


CHAPTER   I. 

PLATE    AND    SOLDERS. 

Phitc — In  the  construction  of  crown-  and  briclgc-work,  g"o](L 
platinum,  or  iridio-platinum  are  used  in  the  following  forms 
and  grades  in  carat,  as  suits  the  requirement  of  the  case  and  the 
preference  of  the  dentist : 

Gold  plate,  24  carats,  from  Xo.  32  to  Xo.  34  U.  S.  standard 
gauge,  for  constructing  the  collars  and  caps  to  collars  of  crown?^ 
and  seamless  crowns,  and  for  l)acking  porcelain  fronts. 

Gold  plate,  slightly  alloyed, — about  23  (.'arats  fine, — in  crown- 
work,  if  less  iiexibility  of  the  metal  is  required. 

Gold  plate,  22  carats,  No.  32  to  JSTo.  34  standard  gauge,  in 
constructing  collars  for  crowns  with  porcelain  fronts  and  all- 
gold  crowns  constructed  in  sections. 

Gold  plate,  20  carats,  in  construction  of  bridge-work. 

Gold  plate,  24  carats,  with  a  very  thin  lining  of  platinum,  oi' 
iridio-platinum  plate,  can  be  used  in  any  of  the  processes  con- 
nected with  crown-  and  bridge-work,  and  is  especially  reconi- 
mendedto  the  inexperienced,  for  the  reason  that  the  melting  of  a 
part  of  a  crown  in  the  soldering  process  is  prevented  by  its  use. 
It  is  formed  by  placing  together  an  annealed  gold  plate  and  a  plat- 
inum plate  (the  gold  about  ]^o.  20  gauge  and  the  i)latinum  Xo. 
30)  and  passing  them  through  a  rolling-mill,  in  which  process  the 
plates  are  welded  and  reduced  to  the  desired  thickness. 

Pure  platinum  rolled  very  thin  is  used  for  forming  caps  to 
collars,  backing  teeth,  and  for  various  purposes  connected  with 
this  class  of  operations.  Iridio-platinum  wire  is  used  for  [livots. 
pins,  or  posts,  being  more  rigid  than  pure  platinum.  A  wire 
of  gold  and  platinum  alloy  is  used  on  account  of  its  elasticity 
for  split  or  spring  pivots  or  posts  in  removable  bridge-work. 

Solders. — Gold  solder,  22  carats  fine,  is  used  for  crown-woik 
20  carats  for  crown-  and  bridge-work. 

249 


250  ARTIFICIAL  GROWN-  AND  BRIDGE-WORK. 

18  carats  is  used  for  crown-  and  bridge-work,  but  this  is  con- 
sidered by  some  too  low  a  carat. 

14  carats  for  strengthening  seamless  crowns :  used  only  in 
crowning  operations. 

Successive  grades  of  solder  from  hard  to  easy  flowing  can  be 
used  in  the  regular  soldering  of  crown-  and  bridge-work ;  gold 
plate  for  the  first,  a  hard-flowing  solder  for  the  next,  and  an 
easy-flowing  one  for  the  finish.  This  avoids  melting  or  flowing 
of  the  gold  at  any  point  previously  soldered. 

Any  grade  of  solder  can  be  made  according  to  the  following 
formula : 

Zinc,  \h  grs. ; 
Pure  gold, 

Silver  solder,  in  quantity  suflBcient  to  make  up  the  22\ 
remaining  parts  in  weight. 

The  quantity  of  silver  solder  used  will  regulate  the  grade  in 
carat  of  the  solder.     Thus  : 

Zinc,  \\  grs.; 
Pure  gold,  20  grs. ; 
Silver  solder,  3  grs., 

will,  by  the  burning  out  of  a  portion  of  the  zinc  in  the  process, 
make  a  solder  about  20  carats  fine. 

By  lessening  the  proportion  of  zinc  from  IJ  grains  to  1  grain, 
tlie  proportion  of  silver  solder  being  kept  the  same,  the  solder 
will  become  harder-flowing  and  a  little  finer. 

Dr.  W.  H.  Dorrance  recommends  the  following  formula  as  an 
alloy  for  the  formation  of  difierent  grades  of  gold  solders,  the 
proportion  of  the  alloy  used  determining  the  melting  point  and 
fineness  in  carat  of  the  solder  : 

1  part  pure  silver  ; 

2  parts  pure  zinc  ; 

3  parts  pure  copper. 

The  silver  and  copper  are  first  melted  together  in  a  crucible 
lined  with  borax  and  the  zinc  added  quickly  in  small  pieces, 
stirring  the  mass  meantime  with  a  pipe-clay  stem.  It  is  then, 
on  the  fumes  of  the  zinc  passing  otf,  immediately  poured  into 
an  ingot-mold  or  into  a  large  wooden  pail  filled  with  water; 
4  grains  of  this  alloy  melted  with  20  grains  of  pure  gold  will 
result  in  a  solder  fully  20  carats  fine. 


PLATE  AND  SOLDERS.  251 

As  a  solder  for  crown-  and  l)ridge-work  constructed  of  22- 
carat  gold  plate,  Dr.  Litch's  formula  is  as  follows  : 

Gold  coin  (ten  dollars),  238  grs.  ; 
Spelter  (or  brazier's  solder),  24  grs.  ; 
Silver  coin,  24  grs. 

This  is  a  proportion  of  about  26  grains  of  pure  copper  and  232 
grains  of  pure  gold  to  the  remaining  48  grains  of  the  alloy,  and 
makes  a  gold  solder  a  little  over  18  carats  fine. 

Dr.  C.  M.  Richmond  originally  used  American  gold  coin  for 
forming  gold  crowns,  rolling  it  out  in  the  form  of  plate.  The 
scraps  he  formed  into  solder  l\v  melting  and  adding  in  small 
pieces  one-fifth  of  their  weight  of  fine  brass  wire  cut  in  small 
pieces,  using  plenty  of  borax. 

Dr.  Low's  formula  for  solder  in  bridge-work  is : 

1  dwt.  coin  gold  ; 

2  grs.  copper; 
4  grs.  silver. 

This  makes  a  solder  about  19  carats  fine. 


CHAPTER  11. 

PORCELAIN     TEETH. 

The  qualities  specially  requisite  in  the  body  of  porcelain  teetli 
for  use  in  crown-  and  bridge-work  are  density,  strength,  and  the 
ability  to  withstand  unaltered  in  form  or  shade  any  degree 
of  heat  to  which  they  may  necessarily  be  subjected.  In  these 
respects  the  porcelain  teeth  of  our  best  American  manufacture 
seem  to  excel,  besides  affording  the  most  artistic  imitation  of 
the  natural  teeth  in  form  and  shade.  They  are  also  distinguished 
by  the  practical  location  of  the  pins. 

In  some  crowning  operations,  where  to  imitate  the  conforma- 
tion of  a  natural  crown  considerable  alteration  of  the  labial 
surface  of  a  porcelain  front  is  required,  teeth  of  English  manu- 
facture may  be  used,  as  the  texture  of  the  porcelain  admits  of  a 
tine  polish  being  given  to  a  ground  surface. 

Teeth  are  sometimes  fractured  in  the  process  of  soldering,, 
caused  by  the  contraction  of  the  backing  when  adapted  over 
the  edges  of  the  porcelain  in  a  curve  instead  of  at  a  right  or 
slightly  obtuse  angle,  or  by  melting  solder  on  some  point  of  the 
porcelain  which  is  unprotected  by  a  backing  of  metal.  The 
solder,  or  the  borax,  as  it  cools,  contracting  on  the  porcelain,  or 
a  very  thin  edge  of  the  metal  covering  it,  will  usually  cause  a 
fracture.  The  porcelain  tooth  has  yet  to  be  made  that  will,  as  a 
rule,  endure  such  extreme  treatment  without  breaking. 


252 


CHAPTER    III. 

MOLDS  AND  DIES. 

Metallic  models  of  fusible  metal  can  be  easily  and  quieklj^ 
formed  for  use  in  crown-  and  bridge-work.  The  melted' alloy 
can  be  poured  into  a  plaster,  moldine,  or  gutta-percha  impression 
taken  in  a  tube  or  impression-tray.  When  a  tube  is  used,  a  strip 
of  paper  should  be  wound  around  it  to  lengthen  the  die. 

The  following  fusible  alloys  of  tin  are  suitable  for  the  purpose  : 


PROPORTIOXS   OI- 

METALS. 

MELTING   POIXT  OK 
THE   ALLOY. 

Tin. 

Lead. 

Bismuth. 

Fahr. 

1 

•2 

2 

286° 

5 

3 

3 

202° 

3 

5 

8 

197° 

Dr.  G.  W.  Melotte,  of  Ithaca,  N.  Y.,  to  whom  is  accorded  the 
credit  of  introducing  the  use  of  fusible  metal  and  the  compound 
called  "  moldine  "  into  crown-  and  bridge-work,  gives  the  propor- 
tions of  his  alloy  in  parts  as — 

Tin,  .5;  Lead,  3;   Bismuth,  8. 

Dr.  Melotte's  moldine,  a  preparation  compounded  of  potter's 
chiy  and  glycerin  (to  which,  when  needed  to  soften  it,  more 
glycerin  can  he  added),  is  very  useful  in  molding. 

A  counter-die  to  a  small  cast  or  die  of  fusible  metal  is  made 
l)y  indenting  a  block  of  lead  with  a  punch,  and  then  driving  the 
cast  or  die  into  it.  Its  use  in  crown-work  is  described  on  pages 
90,  99,  and  103,  and  by  Dr.  Melotte  on  page  209. 

The  following  method  of  forming  a  metallic  model  of  a  pre- 
pared root  or  crown  is  given  by  Dr.  W.  C.  Barrett,  of  Buffalo, 
N.  y,,  who  accords  Dr.  H.  A.  Baker,  of  Boston,  the  credit  of 
being  the  originator  of  it : 

"Copper  is  rolled  down  quite  thin,  and  a  band  three-fourths 

253 


254  ARTIFICIAL  GROWN-  AND  BRIDGE-WORK. 

of  an  inch  wide  wrapped  about  the  root  and  forced  up  under 
the  gum.  A  Ugature  is  passed  around  both;  the  copper  band 
is  burnished  down  and  the  hgature  drawn  tight.  The  copper 
band  will  now  fit  just  as  we  want  the  gold  band  to  do.  Plaster 
of  Paris  is  then  inserted  in  this,  forced  up  against  the  end  of 
the  root,  and  permitted  to  set.  Take  it  off,  and  if  you  use 
Babbitt-metal,  a  piece  of  paper  wrapped  about  it  (tlie  copper 
band)  will  lengthen  it  out  sufficiently,  when  the  metal  may  be 
poured  into  it,  and  thus  a  perfect  model  of  the  end  of  the  root 
will  be  secured.  That  part  that  is  inserted  in  the  copper  tube  is 
the  exact  reproduction  of  the  root  of  the  tooth.  The  model 
will  perhaps  need  a  little  dressing  down  with  a  file,  when  the 
o-old  band  may  be  fitted  around  it  and  soldered,  thus  avoiding 
the  necessitj^  for  the  annoying  and  painful  trying-on  in  the 
mouth." 

Fusible  metal  can  be  used  instead  of  Babbitt-metal. 


Fig.  498. 


CHAPTER  IV. 


SOLDERING. 


InrestiiK'nis  for  soliJering,  and  models 
on  which  the  soldering  is  to  be  done  for 
bridge-work,  are  made  in  calcined  mar- 
ble-dust and  plaster,  in  the  })r()portion 
of  equal  parts  for  models,  and  one  part 
of  plaster  to  two  of  marble-dust  for 
investing.  Sulphate  of  potassium,  used 
in  place  of  common  salt,  but  in  a  smaller 
quantity,  will  cause  the  mixture  to  set 
quickly  and  hard. 

Soldering. — In  soldering  crown-  and 
bridge-Avork  or  sections  of  it  containing 
porcelain  fronts,  the  investment  should 
be  first  uniformly  and  thoroughly 
heated,  and  the  heat  maintained  during 
the  process  of  soldering.  This  is  espe- 
ciall}'  necessary  in  the  final  soldering  of 
gold  crowns  with  porcelain  fronts,  as 
the  solder  is  thereby  flowed  into  the 
interstices  between  the  porcelain  and 
the  ca[»s  and  gives  continuity  of  struc- 
ture to  the  crown.  A  large  piece  of 
charcoal,  concave  on  the  side  to  be  used, 
furnishes  a  good  soldering  support,  as 
it  retains  the  heat.  A  hand  gas  blow- 
pipe, operated  by  a  foot  bellows,  and 
so  constructed  that  the  flame  is  under 
perfect  control,  is  the  most  suitable  (Fig. 
498). 

77/e  i/sc  of  Borax. — In  soldering  in- 
vested sections  of  a   crown    or   bridge 


256 


256  ARTIFICIAL  CROWN-  AND  BRIDGE- WORK. 

together,  borax  which  has  been  reduced  to  a  vitreous  state  by 
heat  and  then  finely  pulverized  is  the  preferred  form  for  its  use. 
Prepared  in  this  manner  it  should  be  sprinkled  on  the  part  pre- 
vious to  the  commencement  of  the  soldering,  and  a  little  added 
at  any  time  it  is  needed  during  the  continuance  of  the  process. 

In  small,  fine  soldering  of  invested  or  uninvested  work,  the 
lump  borax  ground  with  water  on  a  slab  to  a  cream-like  con- 
sistence and  applied  with  the  point  of  a  stick  or  brush  only 
where  it  is  desired  to  have  the  solder  flow,  is  the  most  suitable. 


CHAPTER   V. 


INSTRUMENTS  AND  APrLIANCES. 

The  dentist  who  intends  to  engage  extensivel}^  in  erown-  and 
bridge-work,  and  wlio  desires  to  practice  it  convenientl>'  and 
successfully,  should  siqi[>l_v  liimself  with  all  the  necessary  instru- 
ments, tools,  and  other  appliances.     These  consist  principally  oi 

Fm.  409. 


drills  of  various  styles,  among  them  the  Gates-Glidden  for  root- 
canals;  root-trimming  and  shaping  instruments;  corundum- 
wheels  and  points;  rubber  and  corundum  disks;  a  set  of  steel 
mandrels,  with  a  contracting  plate  and  suitably  shaped  pliers;  a 
supply  of  clamps  of  various  forms  for  use  in  the  many  soldering 
processes;  some  moldine  and  fusible  alloy,  and  an  apparatus  for 
forming  gold  caps  for  use  in  constructing  crowns;  a  Lee  blow- 
pipe or  Knapp's  compound  blow-pipe,  or  both,  for  use  as  is  most 
suitable  or  convenient, 

17  257 


258 


ARTIFICIAL  GROWN-  AND  BRIDGE-WORK. 


The  bench  on  which  the  principal  parts  of  the  work  are  done 
should  be  specially  designed  and  reserved  for  it.  It  should  be 
very  convenient  to  the  dental  chair,  and  if  in  the  same  room 
should  be  situated  a  little  behind  it,  out  of  view  of  the  patient. 
Everything  connected  with  this  bench  should  be  kept  in  order 

Fig.  500. 


and  ready  for  immediate  use.  Such  a  l)ench,  made  of  black 
walnut,  with  a  top  that  can  be  closed  when  not  in  use,  making 
an  unobjectionable  piece  of  furniture,  is  represented  in  Figs. 
499  and  500. 


ERRATA. 

On  page  39,  third  line,  for  "  above  "  road  "  below." 
"       "     159,  eighth  line,  for  "  approximal  "  read  "  palatal." 


1 1^  1 )  E  X. 


Abrasion  of  incisive  edges  of  teeth,  95 
.method  of  forming  crown  for,  116 
Abscess,  chronic  alveolar,  treatment  of,  33 
Acid,  arsenious,  its  use  and  action  in  devi- 
talizing pulps,  26 
Acid  secretions,  platinum  unaffected  by,  98 
Adjuster  for  use  in  cementation  of  crowns, 

129 
Adjustment  of  finished  bridge-work  in  the 

mouth,  144 
Alloy  for  forming  any  grade  of  gold  solder, 

250 
Alloys  of  tin,  their  use  in  crown  and  bridge- 
work,  25.3 
Alveolar  absceFs,  classification  of,  .33 

treatment  of,  33 
Amputation  of  the  apex  of  a  root,  35 
Analysis  of  dentine,  24 
Anatomical  structure  of  dentine,  23 
Anchorage  bars  in  bridge-work,  142,  159,  2311 
manner  of  attaching  to  the  abutiiient<, 

139,  144,240 
manner  of  forming,  144,  160 
Anchorages  for  bridge-work,   preparation 
of,  139,  149,  249 
Dr.  Litch's  method,  212 
Dr.  Parr's,  183 
shell,  151 
Ancient  bridge-work,  133 
Anesthesia  in  ])ulp-extraction,  25 
Anesthetics,  local,  for  application   to  gum, 

34,  36 
Antagonizing   teeth,  preparation   of  their 

cusps,  39 
Antiseptic  agents  in  treatment  of  alveolar 
abscess,  35 
in  treatment  of  devitalized  teeth,  31 
Articulation    for   bridge-work,   manner   of 

taking,  140 
Artificial  crown-work,  17,  41 
the  gold  system,  77 
the  porcelain  system,  44 
Artificial  gum  in  porcelain  bridge- work,  243 


Backings  for   ])orcelain    fronts    in    crown- 
work,  !^5 
Baldwin's  method  of  mounting  crowns,  71 
Bars  for  bridges,  150 
Beers's  crown.  79 
Bing's  bridge-work,  134 
Blow-pipe,  Lee's,  255 

Knapp's  carbo-oxyhydrogon,  205 
Bonwill's  porcelain  crowns,  45 
Borax,    method   of   using    in    crown-    ami 
bridge-work,    in    constructing  root-caps 
and  tubes,  ISS 
Bridge  work,  131 

adjustment  and  insertion,  144 

an  impartial  criticism  of,  134 

cantilever,  158 

cases  illustrating  the  application  of,  1 62 

cementation   of,  128 

construction  of,  137,  147 

detachable,  172,  233 

double-bar,  159 

extension,  155,  195,  243 

foundations  for,  137 

manner  of  taking  impression  and  ar- 
ticulation for,  139 

mechanical    principles    governing  the 
selection  of  abutments,  137 

partial  cap  and  pin,  212 

porcelain,  238 

removable.  172,  187 

removal  of,  171 

with  replaceable  porcelain  fronts,  160 
Brown's  porcelain  crowns,  65 

bridge-work,  238 
Burnishers  for  adapting  collars,  83 

Cementation  of  crown-  or  bridge-work,  128 
Chronic  alveolar  abscess,  33 
Clamps,  soldering.  91 
Collar  contractor,  224 

crowns  hygienically  oon.sidered,  98 

pliers,  225 
Collars  for  crowns,  79,  221 

259 


260 


INDEX. 


Collars,  construction  and  adaptation  of,  7'J 
Construction  of  bridge-work,  137 

detachable  and  removable,  172,  233 

mecbanical  principles  governing,  137 

plate,  1S7 

saddles,  155,  166 

single  and  double  bar,  150,  15S,  159 

small  cases  of,  147 

special  processes  and  appliances  in,  148 
Corundum-wheels  and  points,  37,  38 
Crowns,  artificial : — 

Baldwin's  method  of  mounting,  71 

Bonwill,  45 

Bonwill  cap,  72 

Brown,  61,  65 

Farrar's  cantilever,  96 

Foster,  59 

Gates,  58 

How.  51 

Howland,  59 

Kirk's  method  of  mounting,  70 

Leech,  118 

Logan,  61 

Low, 119 

new  Riehuiond,  fil,  66 

Parr,  117 

Richmond,  182 

Stowell's  metboil  of  mounting,  88 

Van  Woert,  78 

AVeston,  73 

all-gold,  in  sections,  89 

attachments  for  all-gold  and  seamless 
gold,  39,  40,  111,  112 

cementation,  process  of,  128 

contouring  of  collars,  107 

countersunk,  88 

dies  for  use  in  construction  of,  92 

expan<ling,  109 

finishing  and  polishing,  128 

for  separate  molar  roots,  95 

gold  and  porcelain,  for  teeth  with  living 
pulps,  113 

gold  and  porcelain,  without  a  collar,  77 

gold  collar,  79 

gold  seamless  cap,  99,  108 

gold  seamless  contour,  105 

mandrel  system,  221 

partial,  124 

porcelain,  with  collar  attachment,  70 

porcelain,  with  rubber  attachment,  76 

prcjjaration  of  crown  or  root  for.  21,  37 


Crowns,  artificial  (continued): — 

process  of  adjustment  of  gold  contour 

seamless,  108 
remarks  on  the  use  of  collar  or  porce- 
lain crowns,  69,  98 
removal  of,  171 
repair  of,  170 
shell,  151,  156 

Detachable  bridge- work,  172 
i)etachable  porcelain  front,  160 
Devitalization  of  pulps,  25 

heroic  or  instantaneous,  25 

use  of  arsenic  for,  26 
Dies,  87,90,92,99,103,  114 

counter,  90,  103' 

Dr.  Baker's  method,  253 

Dr.  Melotte's.  method  for  forming,  209 

fusible  metal,  253 

manner  of  obtaining  molds   and  dies, 
99,  253 
Diseased  pulps,  classification  of.  requiring 

extirpation,  24 
Disks,  forms  of,  38 
Double  bar-bridges,  159,  239,  240,  241,  242 

244 
Drills,  Gates-Glidden.  form  of  and  method 

of  using,  29 
Dummies,  definition  of,  143 
Dwinelle's  crown,  79 

E.xcision  of  crown,  25 
when  to  avoid,  38 
E.xpansion  of  a  collar  or  crown.  109 
Extension  bar-bridge,  243 
Extension  bridges,  155,  195,  243 
Extirpation  of  pulps,  22,  25 

Farrar's  cantilever  crown,  96 

Ferrules  for  roots  or  crowns,  79 

Files  for  trimming  roots  or  crowns,  38 

Filling  of  root-canals,  31 

Finishing  and  polishing  bridge-work,  144 

crown-work,  128 
Forceps  for  excising  crowns,  26 

for  repairing,  170 
Formulas  for  fusible  metals,  253 

for  gold  solders,   250 
Foster  crown,  59 

Foundations  for  bridge-work,  137 
Fracfnire  of  porcelain  teeth  in  soldering,  262 


IXDEX. 


201 


Fnictured  crowns  and  roots,  treatment  for 

crowning,  121 
Fusible  alloys  of  tin,  253 
Melotte's,  253 

Gates's  crown,  58 
Gold  collar  crowns,  79 

preparing  natural  teeth  for,  38 
Gold  plate  lined  with  platinum,  249 

crown  metal,  249 

solders,  formulas  for,  250 

standard  of  carat  and  gauge  required, 
249 

wire.  249 
Gutta-percha  for  forming  molds  of  crowns 
or  roots,  99 

in  filling  root-canals,  31 

in  preparation  of  roots,  39 

use  of,  for  cementing  crown  and  bridge- 
work,  130 

Hollow  wire  for  posts,  85 

How  crowns,  5  I 

How  screws,  52,  59 

Howland  crown,  50 

Hub-mold,  92 

Hygienic  jireparation  of  the  mouth.  21 

Impressions  of  crowns  or  roots.  47.  99.  102 

cups.  86 

for  bridge-work,  140 

impression  and  articulation  combined. 
140 

materials  for  taking.  80.  139 
Instantaneous  devitalization,  25 
Instruments  and  appliances,  257 
Investments  for  soldering,  255 

in  bridge-work.  143 

in  crown-work,  86 
Iridio-platinum  wire  for  posts,  249 
Irregularities    of    the    toeth,    methods    of 
crowning  in,  122 

Judicial  decision  regarding  the  ])ublio  use 
of  bridge- work,  198 

Kingsley's  method  of  forming  all -gold 
crowns,  91 

Kirk's  method,  70 

Knapp's  methods  in  crown-  and  bridge- 
work,  203 


Lead  counter-dies,  method  of  forming,  253 

Leech's  crown,  118 

Litch's  method  of  crowning,  101 
detachable  bridge,  174 
partial  cap  and  pin  bridge,  212 

Logan  crown,  61 

Dr.  Baldwin's  method  of  mounting,  7  1 

Low  bridge.  1 98 

Low  crown.  119 

Mandrel  system,  220 
Mandrels  for  forming  collars.  SO.  220 
Materials  and  processes  used  in  crown-  and 
bridge- work,  247 

molds  and  dies,  253 

porcelain  teeth,  252 

soldering,  255 
Melotte's  method.  208 
Metallic  dies  and  counter-dies.  253 
Metallic  dies  for  forming   caps  with  cusps 

for  crowns.  92 
Models  for  bridge-work,  140 
Molding,  methods  and  materials  used  in 

90.  99.  103 
Molds  and  dies,  253 
Morrison's  crown,  79 
Mouth,  preparation  of,  21 

Necks  of  teeth,  average  forms  of.  SO.  221 
New  Richmond  crown,  66 

Objections  urged  against  bridge-work,  135 

against  collar  crowns,  98 
Ottolengui  root-reamers  and  facers,  63 
Oxyphosphate  cement.  128 

Parr's  crown.  117 

Parr's  detachable  and    removable  bridge- 
work.  183 
Partial  crowns,  gold.  124 

Dr.  Littig's  method,  127 

])orcelain,  126 
Patrick's  cap-stam])ing  machine,  106 
Pin-bridge,  partial  cap  and,  212 
Plaster  impression  and  articulation,  method 

of  taking,  140 
Plate  and  solders,  249 
Platinum  plate,  249 

wire,  249 

with  gold,  249 
Pliers  for  shaping  collars.  80.  225 


262 


INDEX. 


Porcelain  iml  gold  crown  without  a  collar, 

77 
Porcelain  bridge-work,  23S 
Porcelain   crown   with   gold  collar  attach- 
ment. 70 
Porcelain  crown  with  rubber  or  vulcanite 

attachment,  76 
Porcelain  crowns,  remarks  on  the  use  of,  69 
Porcelain  faces  for  crowns,  140,  160 
Porcelain  teeth,  selection  of,  252 

some  causes   of  fracture  in   soldering, 
252 
Pouring  fusible  alloy  or  metal,  manner  of, 

99 
Preparation,  special,  of  badly  decayed  teeth 

and  roots,  39 
Pulp,  diseases  of,  requiring  extirpation,  24 
instantaneous  devitalization,  with   ex- 
cision of  crown,  25 
preservation  or  devitalization,  23 
Pulpless  teeth,  their  treatment  and  disin- 
fection, 29 
Punch  forceps  for  riveting,  for  use  in  re- 
pairing bridge-work,  170 

Removable  or  detachable  bridge-work,  172, 
233 

Dr.  Litch's,  174 

Dr.  Parr's,  183,  184 

Dr.  Richmond's,  182 

Dr.  Starr's,  177 

Dr.  Waters's,  1 82     . 

Dr.  Winder's,  172 

methods  of  forming  attachments  for,  185 
Removable  plate  bridges,  187 
Removal  of  crown-  and  bridge-work,  171 
Repair  of  crown-  or  bridge-work,  170 
Retaining-pin  for  all-gold  crown.  111,  1  12 
Richmond  crown,  84 

Root-canal,  antiseptic  agents  for  treatment 
of,  31 

dryer,  31 

method  of  filling,  31,  32 

method  of  treatment,  29 
Root-reamers  and  facers,  Ottolengui's,  63 
Root-trimmers,  Starr's,  179 
Roots  intervening  between  abutments,  150 
Roots,  special  preparation  of  badly  decayed, 

39 
Rubber  or  vulcanite  attaohrai'-nt   for  crown, 
76 


Rules   governing  the  insertion  of   bridge- 
work,  137 

Seamless  gold  collars,  222 
Seamless  gold  crowns,  99 

method  of  contouring,  105 

method  of  forming  from  an  impression, 
102 

process   of  adjustment  and    insertion, 
108 
Screws  for  use  in  crown-work,  52,  59 
Sectional  crowns,  84,  106 
Sections    of   bridge-work,  construction    of 

144,  147,  149,174 
Self-cleansing  spaces,  141 
Shaping  teeth  and  roots  for  crowning,  pro- 
cess of,  37 
Shell  anchorage  or  crown,  151 

seamless,  153 
Shoulders  on  the  anterior  teeth,  148 
Slots  for  anchorage  bars,  139,  149,  239 
Solder,  gold,  formulas  for,  250 

Dr.  Dorrance's,  250 

Dr.  Litch's,  251 

Dr.  Low's,  251 

Dr.  Richmond's,  251 
Soldering,  manner  of,  144,  255 
Solid  gold  crowns,  148 

Special  forms  and  methods  in   crown-  and 
bridge-work,  117 

Dr.  Knapp's,  203 

Dr.  Low's,  119,  199 

Dr.  Melotte's,  208 

mandrel  system,  221 
Special  preparation  of  badly  decayed  teeth 

or  roots,  39 
Spur  support  in  bridge-work,  158 
Stamping  press  for  caps,  106 
Starr's  method  of  detachable  bridge-work^ 
177 

root-trimmers,  179 
Strengthening  gold  seamless  crowns,  110 
Syringes,  hot-air,  30 

abscess,  34 

Table  of  fusible  alloys,  253 

Teeth,  porcelain,  252 

Temporary  attachment  of  bridge-work,  130 

Thickness  of  ])late  suitable  for  crown-work 

80,  249 
Tin,  alloys  of,  253 


INDEX.  263 

Treatment  of  clironic  alveolar  abscess,  33  Weston's  crown.  73 

preparatory,  of  the  mouth,  21  Winder's  detachable  bridge-work,  172 

Trying  in  bridge-work.  141  Wire  for  posts  or  i)ivots,  85,249 

Warping  of  bridge-work  in  soldering,  145  Zinc,  oxy])hosphate  of,  for  cemonting.  128 

\Vaters's  removable  bridge- work.  182 


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